IdahoDoug

I copied and pasted the below article from Motor Trend's website as it has useful information on Toyota vintage axles - splines, widths, etc. Sorry there's some font and formatting screwups and extra space but the text is all there. I deleted ads and such as best I could. One day, I plan to upgrade my Sunrader's suspension and may even convert it to 4WD for light offroading and the ability to be solo self supporting in remote areas where 4WD is needed to guarantee mobility. Information I've also gleaned from calling the Toyota dealer includes that my 1982 4 speed manual Sundrader came with a RN44HVY axle with 4:11 gears. The original wheel bearing part number was 97144-06308, which is the same p/n as the regular Pickup of the day. This p/n later superceded to 90363-40020-77 which is what you'd order as of this writing. Here's the article text: Toyota pickup axles are renowned for their light weight, low cost, and high strength. Although they don't offer the ground clearance of portal axles or the massive ring gear of a Corporate 14-bolt, these axles are popping up under a wide variety of vehicles beyond Toyotas, including Jeeps, Samurais, and buggies, because of the features mentioned above. As good as they are from the factory, like most components they can still benefit from advances made in the aftermarket. Stock Front Axle Toyota used a solid front axle in the '79-'85 pickups and 4Runners. All of these axles were 55.5 inches wide from wheel mounting surface (WMS) to wheel mounting surface and came with solid front disc brakes and closed knuckles with Birfields. These axles also came with push-pull steering and a torque-rod bracket welded to the housing. They use the same 8-inch third member and 1-5/16-inch axleshafts as the rear axle, simplifying part swapping. The Birfields are 30-spline at the hub, and the inner axles are 27-spline at the Birfield end and 30-spline at the differential end. Earlier axles had no trussing on the long side, but over the years Toyota increased the size of the truss under the housing until eventually it spanned the long side of the housing by 1984. SEE ALL 17 PHOTOS FRONT AXLE UPGRADES AFTERMARKET BIRFIELDS BY FAR THE WEAKEST LINK IN TOYOTA AXLES ARE THE STOCK BIRFIELDS. THESE JOINTS HAVE LIMITED ANGULARITY AND ARE PRONE TO CRACKING WITH THE STEERING AT FULL LOCK AND POWER APPLIED. LONG'S ENTERPRISES DEVELOPED LONGFIELDS THAT ADDRESS ALL OF THE FACTORY SHORTCOMINGS. THE LATEST GENERATION OF LONGFIELDS ARE 30-SPLINE FROM THE DIFFERENTIAL TO THE HUB AND ARE MADE FROM CHROME-MOLY. THE INNER RACE IS MACHINED FROM 300M AND IS SMALLER THAN STOCK TO ADD THICKNESS TO THE OUTER BELL. IN ADDITION TO THE STRENGTH, LONGFIELDS ARE ABLE TO PROVIDE A MUCH TIGHTER TURN RADIUS THAN STOCK BIRFIELDS DUE TO THEIR TAPERED DESIGN. INNER AXLES AFTERMARKET BIRFIELDS USED IN CONJUNCTION WITH STOCK AXLESHAFTS CAN TRANSFER THE WEAK LINK TO THE SPLINES WHERE THE SHAFT MATES WITH THE BIRFIELD. POLY PERFORMANCE SELLS CHROME-MOLY INNER AXLESHAFTS THAT DO NOT NECK DOWN LIKE THE STOCK SHAFTS AND WHICH ELIMINATE THE NEED FOR A C-CLIP TO RETAIN THE AXLE. SEE ALL 17 PHOTOS UPGRADED HUB STUDS WHEN HUB STUDS SHEAR, THEY OFTEN RENDER THE WHEEL HUB USELESS. IN ORDER TO CURE THIS PROBLEM, FRONT RANGE OFF-ROAD FABRICATION DEVELOPED HARDENED CHROME-MOLY STUDS THAT FEATURE ROLLED SPLINES AND INCLUDE HIGH-QUALITY LOCKNUTS FOR PROPER RETENTION. CHROME-MOLY HUBS AFTER UPGRADING THE BIRFIELDS AND INNER AXLES, THE STOCK HUBS BECOME THE WEAK LINK. DRIVE FLANGES FROM AN FJ80 LAND CRUISER CAN BE USED TO REPLACE THE HUBS, BUT LONG'S ENTERPRISES HAS A MORE PRACTICAL SOLUTION FOR THOSE WHO DON'T WANT THEIR FRONT DRIVESHAFT SPINNING ALL THE TIME. LONG DEVELOPED 4340 CHROME-MOLY HUB GEARS THAT ARE SIGNIFICANTLY STRONGER THAN STOCK AND WON'T STRIP THE SPLINES OFF OF YOUR HIGH-DOLLAR AFTERMARKET BIRFIELDS. SEE ALL 17 PHOTOS BEEFED STEERING STOPS THE STOCK STEERING STOPS CONSIST OF A SMALL PIECE OF TRIANGULAR METAL STRAP-WELDED TO THE HOUSING. ADDING HUGE TIRES AND HYDRAULIC-ASSIST STEERING CAN BEND THE STOPS, CAUSING THE BIRFIELDS TO BIND AND BREAK. TO PREVENT THIS, INCHWORM GEAR MAKES FULLY BOXED STEERING STOPS OUT OF HEAVY-GAUGE STEEL. THE NEW STOPS WELD DIRECTLY IN PLACE OF THE FACTORY STEERING STOPS AND OFFER GREATLY INCREASED STRENGTH. CROSSOVER STEERING FROM THE FACTORY, SOLID-AXLE TOYOTAS CAME EQUIPPED WITH PUSH-PULL STEERING THAT WAS USED IN CONJUNCTION WITH A TORQUE ROD. THE TORQUE ROD LIMITS ARTICULATION, BUT REMOVING IT CAN RESULT IN BROKEN DRAG LINKS AND STEERING ARMS. ALL-PRO OFF-ROAD OFFERS A KIT THAT REPLACES THE ENTIRE STEERING SYSTEM WITH A CROSSOVER CONFIGURATION USING AN IFS TOYOTA STEERING BOX, FORGED STEERING ARMS, 0.250-WALL DOM LINKS, AND 23MM FJ80 TIE-ROD ENDS. THE TIE ROD IS ALSO MOVED ABOVE THE SPRINGS AND BEHIND THE AXLE FOR GREATER PROTECTION ON THE TRAIL. SEE ALL 17 PHOTOS UPGRADED KNUCKLE STUDS JUST AS WITH THE HUB STUDS, KNUCKLE STUDS CAN SHEAR AS WELL. THIS IS OFTEN AN ISSUE WHEN WIDE, HEAVY TIRES ARE USED IN CONJUNCTION WITH RIMS WITH MINIMAL BACKSPACING. FRONT RANGE OFF-ROAD FABRICATION IS THE SOLE DISTRIBUTOR FOR ARP KNUCKLE STUDS. THE NEW STUDS ARE HARDENED CHROME-MOLY AND FEATURE ROLLED SPLINES FOR ADDITIONAL STRENGTH. SEE ALL 17 PHOTOS BRAKE UPGRADES THE FACTORY BRAKE CALIPERS AND SOLID ROTORS ONLY DO A MARGINAL JOB OF STOPPING SMALL STOCK TIRES, SO WHEN YOU ADD MORE WEIGHT AND LEVERAGE THEY ARE REALLY OVERWHELMED. VENTED ROTORS FROM AN '81-OR-LATER FJ40 CAN BE USED IN CONJUNCTION WITH CALIPERS FROM AN IFS PICKUP FOR IMPROVED BRAKING FORCE AND LESS FADE. THE LATER V6 CALIPERS HAD LARGER PISTONS THAT PROVIDE MORE BRAKING FORCE THAN THE EARLIER IFS CALIPERS. ALL-PRO D60 HYBRID MANY OF THE AFOREMENTIONED UPGRADES HAVE BEEN BUNDLED INTO ONE BEEFY AXLE FROM ALL-PRO OFF-ROAD. ALL-PRO REPLACES EVERYTHING FROM THE KNUCKLES OUT WITH 1-TON COMPONENTS. THE COMPANY'S HYBRID AXLE FEATURES F-450 U-JOINTS, BEARINGS, AND HUBS WITH WILWOOD CALIPERS AND ROTORS THAT PROVIDE INCREASED STOPPING FOR LARGE TIRES. THE BRAKES FIT UNDER 15-INCH WHEELS AND EVEN RETAIN THE STOCK 6X5.5 BOLT PATTERN. HIGH-PINION THIRD MEMBERS FJ80 LAND CRUISERS USED A FRONT THIRD MEMBER THAT IS INTERCHANGEABLE WITH THE SOLID AXLES FOUND IN PICKUPS AND 4RUNNERS. THE LAND CRUISERS USED A HIGH-PINION THIRD MEMBER WITH A REVERSE-CUT RING-AND-PINION THAT IS STRONGER THAN THE LOW-PINION THIRD MEMBER USED IN STOCK FRONT AXLES AND WHICH OFFERS 4 INCHES MORE GROUND CLEARANCE FOR YOUR DRIVESHAFT AND PINION FLANGE. SEE ALL 17 PHOTOS AXLE TRUSS LARGE TIRES INCREASE LEVERAGE, WHICH CAN RESULT IN BENT AXLEHOUSINGS, PARTICULARLY IF THE VEHICLE IS JUMPED. ALL-PRO OFF-ROAD SELLS A TRUSS THAT CAN BE WELDED TO THE TOP OF YOUR AXLEHOUSING FOR IMPROVED RIGIDITY WITH NO LOSS OF GROUND CLEARANCE. STOCK REAR AXLE TOYOTA USED A SOLID REAR AXLE WITH AN 8-INCH RING GEAR AND 1-5/16-INCH 30-SPLINE AXLESHAFTS EXCLUSIVELY THROUGH '95, AND EVEN LATER IN SOME TACOMAS, T100S, AND 4RUNNERS. EARLY AXLES WERE 55 INCHES WIDE TO MATCH THE FRONT SOLID AXLE AND INCREASED BY 3 INCHES WHEN THE SWITCH TO IFS WAS MADE IN 1986. WITH THE ADDED WIDTH IN '86, THE AXLETUBES GREW LARGER AND THE BRAKE DRUMS WERE ALSO ENLARGED FROM 10 INCHES TO 11.6 INCHES. ALL PICKUPS AND '89-AND-EARLIER 4RUNNERS USED LEAF SPRINGS, WHILE LATER 4RUNNERS USED A FOUR-LINK AND COIL-SPRING SUSPENSION, MAKING THESE AXLES MORE DIFFICULT TO RETROFIT INTO OTHER VEHICLES. REAR AXLE UPGRADES V6 THIRD MEMBERS THE THIRD MEMBER FROM A V6 OR 22RTE TURBO-POWERED TRUCK BOLTS DIRECTLY IN PLACE OF THE STANDARD FOUR-CYLINDER THIRD MEMBERS YET IS STRONGER DUE TO THE FOUR SPIDER GEARS, LARGER RING-AND-PINION, LARGER BEARINGS, AND STIFFER THIRD-MEMBER HOUSING. UPGRADED AXLESHAFTS POLY PERFORMANCE OFFERS UPGRADED AXLESHAFTS MADE FROM 4340 CHROME-MOLY. THE SHAFTS ACCEPT STOCK BEARINGS AND BRAKES AND USE ROLLED SPLINES AND A TAPERED DESIGN FOR MAXIMUM STRENGTH. SEE ALL 17 PHOTOS SEE ALL 17 PHOTOS REAR DISC BRAKES LARGER-THAN-STOCK TIRES CAN LEAD TO INCREASED BRAKING DISTANCES DUE TO THE ADDED LEVERAGE AND WEIGHT OF THE BIGGER MEATS. ALL-PRO OFF-ROAD HAS A BOLT-ON REAR DISC-BRAKE KIT THAT PROVIDES SHORTER STOPPING DISTANCES, EASIER MAINTENANCE, AND LESS UNSPRUNG WEIGHT. FULL FLOATER SEVERAL OF THE ABOVE IDEAS HAVE BEEN INTEGRATED INTO ONE COMPREHENSIVE PACKAGE FROM FRONT RANGE OFF-ROAD FABRICATION. THE KIT CONVERTS THE REAR SEMIFLOATING AXLE TO A FULL FLOATER USING CUSTOM-MACHINED AND FACTORY TOYOTA COMPONENTS. IN ADDITION TO THE INCREASED LOAD-BEARING CAPACITY AND SAFETY, THE FROR FULL-FLOATER KIT ALSO INCORPORATES CHROME-MOLY AXLESHAFTS AND DISC BRAKES FOR EVEN GREATER STRENGTH AND PERFORMANCE. AXLE TRUSS ADDING AN AXLE TRUSS CAN STRENGTHEN YOUR AXLEHOUSING AND RESIST BENDING THE TUBES - PARTICULARLY IF YOU LIKE TO JUMP YOUR TRUCK. DOWNEY OFF-ROAD OFFERS A WELD-ON TRUSS THAT INCORPORATES A POLYURETHANE BUSHING IN THE MIDDLE TO ACCOMMODATE A TRACTION BAR AS WELL. UPGRADES FOR FRONT AND REAR AXLES SOLID SPACERMOST AFTERMARKET GEARSETS COME WITH A CRUSH SLEEVE THAT FITS BETWEEN THE PINION BEARINGS AND IS COLLAPSED DURING THE INSTALLATION PROCESS TO SET PRELOAD. A SOLID SPACER IS AVAILABLE FROM ALL-PRO OFF-ROAD THAT ELIMINATES THE POSSIBILITY OF EXCESS BACKLASH AND THE NEED TO RETIGHTEN THE PINION NUT. SEE ALL 17 PHOTOS ELECTRIC LOCKERS TOYOTA USED AN 8-INCH CENTERSECTION WITH A FACTORY ELECTRIC LOCKER IN TRD TACOMAS AND SOME 4RUNNERS. WITH MINOR HOUSING MODIFICATIONS, THIS THIRD MEMBER CAN BE RETROFITTED INTO ANY 8-INCH HOUSING FOR AN OPEN DIFFERENTIAL ON THE ROAD WITH THE TRACTION OF A SPOOL AT THE FLIP OF A SWITCH. FZJ80S EVEN CAME WITH AN OPTIONAL HIGH-PINION ELECTRIC LOCKER IN THE FRONTEND. FACTORY RATIOS WERE 4.10, 4.30, AND 4.56, BUT INCHWORM GEAR CAN SET YOU UP WITH AN ELECTRIC LOCKER AND THE RELATED WIRING IN ANY GEAR RATIO YOU DESIRE. SEE ALL 17 PHOTOS LOW-PROFILE DRAIN PLUGS THE FACTORY DRAIN PLUG ON TOYOTA HOUSINGS IS A HEX-HEAD PLUG THAT WE HAVE SEEN GET KNOCKED LOOSE ON MORE THAN ONE TRAIL RIDE. BUDBUILT STOCKS LOW-PROFILE DRAIN PLUGS THAT USE AN ALLEN WRENCH FOR REMOVAL, SO THEY WILL STAY PUT ON THE TRAIL AND YOU CAN STILL REMOVE THEM WHEN NECESSARY. SEE ALL 17 PHOTOS DIFF ARMOR THE FACTORY DIFFERENTIAL HOUSING IS STAMPED STEEL AND CAN BE DENTED AND CONTACT THE RING GEAR DURING HARD CONTACT WITH ROCKS. ALL-PRO OFF-ROAD'S DIFF ARMOR WELDS TO THE FACTORY HOUSING AND PROTECTS THE RING GEAR FROM ANY IMPACTS. 4CRAWLER SHAVED DIFF A MORE COMPLICATED WAY TO ARMOR YOUR AXLEHOUSING: REMOVE THE DRAIN PLUG COMPLETELY AND GAIN GROUND CLEARANCE WITH 4CRAWLER'S HIGH-CLEARANCE AXLE KIT. THIS KIT REQUIRES YOU TO CUT OFF THE BOTTOM OF YOUR AXLEHOUSING AND WELD IN THE SUPPLIED PIECES TO REALIZE THE ABOVE BENEFITS. SEE ALL 17 PHOTOS DIAMOND AXLEHOUSINGS THE ULTIMATE IN STRENGTH, FRONT OR REAR, COMES IN THE FORM OF DIAMOND AXLES AXLEHOUSINGS. THESE ALL-NEW HOUSINGS FEATURE 1/2-INCH-THICK MOUNTING FLANGES, 3/4 INCH MORE CLEARANCE THAN STOCK HOUSINGS, AND 1-INCH-THICK STEERING STOPS ON FRONT HOUSINGS. DIAMOND AXLES CAN BE ORDERED IN CUSTOM WIDTHS WITH A VARIETY OF OPTIONS INCLUDING DANA 44 OR DANA 60 KNUCKLES, SEMIFLOATER OR FULL-FLOATER ENDS, AND DRIVER- OR PASSENGER-SIDE DROP.

I have a feeling I know why, but I'm wondering why the Axle forum comes up as a "404 dead link"? As a newcomer to the forum, I was looking forward to hearing what the issues are, how to avoid or solve them, and hopefully what others have successfully done to mitigate things. My plan is to either go single tire, or at 32k put on new bearings and then monitor for the looseness that precedes a bearing issue. Regardless - curious about that forum. Cheers.

Wow, sage advice on a random Thursday as I sit waiting my turn at the barber shop. Very very good point right there.

No trim or covering in the cabover contributes to its structural strength. Good luck finding panels. Use 3m automotive grade adhesive / contact cement or other if you cover the new part with padded vinyl or cloth. Lesser glues not designed for the heat of a vehicle closed up on a hot day will let go. Key is auto grade. Send pics when done!

Should it prove useful, I made some similar panels for our VW Vanagon a few years ago. At Home Depot they sell 4X8 sheets of this fiberboard a little thicker than what's in our Sunrader's for side panels you are working on. It came in an indoor grade and a water resistant grade. I used the latter and found it easy to cut and work with. It also took paint nicely and blended in well with the rest of the interior - looked factoryish. It will accept a staple and will also do an OK job of holding a screw.

Fred, Thanks - correct I have the G082 rear axle. For reference for others, this is the weaker 5 stud axle with the 'foolie' dual tire setup that proved not up to the task. Wheel bearings would overheat, fail and the wheel separates. I'm planning to keep using it as my Sunrader has only 32k miles and will be monitoring it for the slack that precedes bearing failure. So also for reference, the dealer tells me the factory Toyota P/N for the bearings is: 90363-40020-77. They are no longer available through the Toyota parts system but many sources have them. So, to my question on DIY these. Has anyone been able to replace these with a press and piece of pipe, etc? I watched a guy make a tool on Youtube, but I can't weld. Seems like a heavy plate with 4 holes in it to span my press would be strong enough to do it? Dunno...

I have a press, but wondering if anyone's done the replacement without the tool? Thanks for verifying availability. Dizzying array of bearings for Totota truck rr axles - anyone have the p/n for the 5 lug foolie axle bearings?

Thanks. Looks like there is a tool available for pressing the axle off. Is that a necessity or is there a work around with common items around the shop?

Yeah, just learned these are the "replace and forget" type rear wheel bearings. Bummer. All my Toyota LandCruisers over the years were the repackable type, so I was hoping these would be also - allowing me to closely monitor the rear wheel bearings for issues by annual repacks or so.

Happy thats considered an alternative - any 15" wheel favorites come to mind? I'm interested in basic looking steel - not a fancy wheel guy.. I was actually going to lift the vehicle a bit - using the torsion bars twisted tighter up front and adding airbags at the rear for those days we find ourselves on poor dirt/forest roads. Which happens a lot. Just an inch can make all the difference.

New member hello and intro here. So, I've always liked these clamshell designs, and I have a few classic Toyotas and once worked at Toyota HQ in the US. We've been camping and adventuring around the Pacific NW and Canada for 15 years in classic VW Vanagons. First a Syncro, and now a Wolfsburg tin top. We always marvel at the space efficiency as it has an actual queen bed, and with a cassette toilet it pretty much makes a perfect all weather base camp. So when an 82 Sunrader with 32k miles popped up on CL, we went to look on Sunday morning. The snow has pushed the roof down, cracking the roof vent seals and leaking water into the interior for years. The cabinetry is warped, the floor is spongy, the original wood veneer ceiling is coming down. We hemmed and hawed about it, but I'd brought overalls to crawl under and to my surprise there is an intact metal floor under the interior floor, which meant floor replacement was simply a matter of laying down fresh plywood as a base. Interestingly, there was no mold, and no mildewy smell - defies logic. The Toyota cab is pristine - nearly new looking. It's also a 4 speed, and combined with the venerable 22R means I will have zero work on the chassis. So we bought it for a crazy low price of $1500 figuring we couldn't go wrong. It started right up, and drove like a champ all the way home. One mishap was it was nearly out of gas so I stopped to fill it up. More fuel ended up on the ground than in the tank. I bent down and could see a pop can with hose clamps held onto the filler hose in the wheelwell. With a 6 foot diameter pool of Premium rapidly spreading. I opted for the cowards way out and simply hopped in and left rather than needing to fill out some environmental spill paperwork or whatever the station might have had in mind for me. I watched a few videos on people stripping them out down to the bare fiberglass and building an interior, so that's what our plan is. We want to keep the bath/shower as it's right sized, and the enclosure looks very well designed against leaks. We'll also keep all the appliances and tankage. The ceiling is a mess and I will be gutting the interior to redo it - so months away from actual use of the vehicle. The moisture also messed up most of the cabinets on the right side of the vehicle, so I'll be using them just for templates to make new, and shrinking them by a few inches here and there to open things up. I actually think the Sunrader has too much hard space dedicated to storage, which significantly shrinks the interior. By that, I mean the overhead cabinetry is a little much, and as ours is a rear dinette model, the overhead cabinets back there seem to shrink the space. The lower level cabinetry is pretty huge, and the hanging closet is as well. The flooring is soft in spots as well, so will lay down new plywood and start from there. I'll find a way to add some foam insulation to isolate the wood thermally from the metal floor, but I suspect I will end up with a thinner solution than the original with today's higher grade and stronger choices. Good news on the classic sagging roof is that I experimented yesterday with a floor jack to see how easy/hard it is to move the roof back up and it's pretty easy. So I'm going to add curved external metal ribs to hold its shape and make it strong enough to walk on and load kayaks, etc. A custom welded aluminum rack might also do it, but that requires a level of precision I'm not sure can be achieved. Meaning if I mount the rack and then find I cannot get the roof pulled all the way up to mate with the rack's curved crossmembers, I will have created a leakage and wind noise nightmare. My plan is to make a curved "ram" to push up the roof every 18" or so using the floor jack inside. And curved 1" aluminum pipes up on the outside I'll form with a tubing bender from Harbor Freight. I haven't ruled out other options for those strengthening external ribs, so let me know if you have other ideas. I don't want to do internal ribs due to the loss of headroom, and the need to have them anchored to the sidewalls - creating issues with each rib going through cabinets, the bathroom, etc. The interior ceiling will have a thick 1" wide aluminum strip to spread the load of the fasteners against fiberglass. I'll bed the ribs in 3M Marine bedding compound for a decade of waterproof sealing. The emphasis on the roof is twofold. First, I'm not sure anyone's ceiling is near the height it was and I was amazed how high I was able to raise it with my experiment. It really changed the feel in there - I lifted mine probably 2.5 inches, and I really liked that sudden open feeling where I had a few inches above my head, vs brushing it with my hair (5'10"). Second, we are still active and will carry kayaks, it can then handle our snow loads, and we may also sit up there. So I like the idea of being able to turn the roof into a utility area. I'll install stout tiedowns on the ribs for securing things, and may build a simple pulley system to lift kayaks up the side to roof level - again using the ribs as a solid hard point/foundation. Lots to do, but those are the bones of a plan at this point. I've read some of the forum info, also. One item I'm trying to figure out is what does this thing weigh with all the tanks full as I'm looking at tires? Ours does not have the 1 ton axle and I don't plan to change it at this point as after one season of use, I may consider lifting it and converting it to 4WD with solid f/r axles. Since the axle issue is rooted in wheel bearing failure, I'll see if the rear bearings are (hopefully) the old fashioned repackable type and just keep them in good nick for now. So, happy to be here and happy to see some other nice folks willing to share information and the like. I'm pretty mechanical, and hope to contribute on that end as well! Tally Ho.

Hey, those are some great suggestions. Kudus to Toyota for making it relatively easy to remove the part. Inside the cabinet, the hose goes through a little dog house and after removing this, access was good. As I just got the beast home from buying it Sunday, I don't have to move it for any reason until I register it. So I have time to wait for the hose I ordered on eBay and see if it fits properly. Cross your fingers.

Thanks for the thought. Unfortunately, this hose is a different diameter on each end. So, bulk hose won't work. I have to either find another model vehicle that is roughly the same length hose and uses the correct end diameters, or find an original hose made for the Sunrader. I found one on eBay that says it is going to work, but I don't have much faith in it, frankly. So, have others had to replace their fuel fill hoses and found a solution?

I am a former Product Planner for General Motors, as well as Lexus and would caution against adding an air opening on the rear of the Sunrader. We had to be very deliberate in preventing exhaust fumes from getting into the interior on automobiles, so you'll see if you remove a bumper, for example, that all air openings on the rear to dry the body cavities will have simple one way flapper valves that shut when air tries to come in. A larger, more boxy shape increases the danger of this reverse air coming in the rear of a vehicle underway, vs a slippery car. Linda is correct on the roof vents not adding much/any to the aero drag, but it would add drag if placed on the slope of the cab over. To the OP's question. When sitting, having an air exhaust fan somewhere will obviously pull air into the cabover bunk, so that will work. Perhaps put it on the side, and if you don't have a preference - behind the stove, where it would double as a massive exhaust fan to pull cooking smells and cooking heat immediately outside? Interesting thought, and I have been pondering using a pair of strong computer fans on our VW Vanagon to pull night air through the van while sleeping. They're super quiet, which is why I was looking at/considering them. Plus programmable, highly variable, etc. Let us know what you come up with!

They are not structural at all. The cabover is an extremely stout structure and these side panels are purely cosmetic. Consider adding a power outlet for phone charging near you while sleeping, etc since you have the area open and are replacing the panel.

So, this is also my first post since joining and I'll do a more complete one on the General forum. Bought it yesterday somewhat on a whim as it needs an interior gut and replace, but it has a crazy 32k miles on it and I think I'm up for the camper refit challenge. On the way home, I made an interesting discovery at a gas stop. It had near zero fuel from the buyers and we live 50 miles away. But when I started filling it, about as much gas ended up on the pavement as in the tank, so I stopped at 2 gallons. Kept my fingers crossed but pretty impressed at the duress infused fuel economy as we made it. This morning I crawled under and a rodent has chewed a 1" diameter hole in the rubber hose that goes from the filler hole to the tank. Anyone know if it's available? Toyota no longer makes the part for a 1982 Pickup, but I was unsure if it is the same when on a cab/chassis that becomes a Sunrader. My instinct says yes as I suspect it arrived in the US as a cap/chassis with an intact fuel tank and the camper was built around it. Anyone know? Good sources for Sunrader parts? Thanks in advance. Doug