thefreedwellers Posted June 12, 2015 Share Posted June 12, 2015 Hi all, we are completely new to the Toyota motor home community! About a month ago we purchased a 1986 Sunrader 18′ Shorty, and are working on getting it comfy and safe for a cross-country road trip. The original rear differential was very loud and needed to be replaced. Our mechanic in NY found one and put it in. However, it is pretty rusty and he had to epoxy part of it. We have since moved to MA. We drove it about 70 miles with our "new" rear diff and then noticed gear oil all over it and above it. We are assuming the problem may be with the bearings and/or seal. There is some up and down play in the drive shaft. Now we are stuck with a bad rear diff, 70 miles from the mechanic who put it in. We took it to a mechanic here in MA who cleaned the rear diff and checked the gear oil, which was only down about 3/4". There are some small bits of metal in the oil and some noise when driving. Our questions: 1. Do you think it's safe to drive 70 miles to our NY mechanic who put the bad rear diff in? Potentially getting some of our money back or the rear diff fixed for free/cheap. 2. Give up on the one we have and have a mechanic here find and install a different one? 3. If we decide to get a new one: does anyone around the Northeast have a rear diff in good shape that they want to sell? We would be willing to travel max 2 hrs each way. Thanks for the help! Quote Link to comment Share on other sites More sharing options...
zero Posted June 12, 2015 Share Posted June 12, 2015 The original rear differential was very loud and needed to be replaced. Our mechanic in NY found one and put it in. However, it is pretty rusty and he had to epoxy part of it. We have since moved to MA. We drove it about 70 miles with our "new" rear diff and then noticed gear oil all over it and above it. We are assuming the problem may be with the bearings and/or seal. There is some up and down play in the drive shaft. Now we are stuck with a bad rear diff, 70 miles from the mechanic who put it in. We took it to a mechanic here in MA who cleaned the rear diff and checked the gear oil, which was only down about 3/4". There are some small bits of metal in the oil and some noise when driving. I'm wondering why in heck the "mechanic" did not just fix the original differential. It's not something that "goes bad" as an entire unit. When it makes noise, a competent mechanic will take it apart and fix the damn thing - that is - replace whatever bearings or gears have gone bad. Since the Toyota uses a "Hotchkiss" type unit - it is fairly easy to just remove the entire differential and just replace it as a whole. Many backyard mechanics will do that if a good entire unit is available. I don't like doing that UNLESS that unit came out of a truck got to run first. Now - if your mechanic discovered all the bearings bad, and the ring & pinion burnt up - then getting an entire used replacement might be cheaper in the long run. About what you have now. The bearings on the input/pinion shaft (where the driveshaft hooks to) must be adjusted properly. When so - there will be absolutely NO play. I've seen many good ones get ruined when someone attempts to just install a new pinion seal. It is very easy to over-tighten the pinion nut after installing a new seal, putting too much preload (crush) on the bearings, and burning them up pretty quickly. DID your mechanic put a new pinion seal in that used differential? If so, I bet he got it too tight and the pinion bearings are burnt up. If so, NO, I would NOT drive it. I don't know where in NY you are. I just junked a perfectly good Toyota truck differential with a 4.11 to 1 ratio. Your's is likely a 4.10 to 1, or a 4.11 to 1. I let a junk guy in Stamford NY have it (Delaware County in central NY). If you are near that area, he might still have it there. OR - just call a junkyard. A standard Tacoma differential, or older pickup or Hilux will bolt right in and it makes no difference if a dually full-floater with 6 lug wheels or a single-wheel semi-floater with 5 lug wheels. The Hotchkss center-sections are interchangeable. What should be done now - is to pull what you have apart and see what is actually wrong with it. Burnt bearings sound different then scorched gears - but it's hard to describe with simple words. When you said the replacement differential has rust holes - you've got me wondering. Was just the center Hotchkiss section replaced - or was the entire rear axle assembly replaced? Hopefully not the latter? I ask because the center-section is pretty thick cast-iron and steel and it's hard to imagine one gettting rust holes. The banjo-axle assembly - yes - since it is made of thin steel. Quote Link to comment Share on other sites More sharing options...
Donnie Posted June 12, 2015 Share Posted June 12, 2015 Hi all, we are completely new to the Toyota motor home community! About a month ago we purchased a 1986 Sunrader 18′ Shorty, and are working on getting it comfy and safe for a cross-country road trip. The original rear differential was very loud and needed to be replaced. Our mechanic in NY found one and put it in. However, it is pretty rusty and he had to epoxy part of it. We have since moved to MA. We drove it about 70 miles with our "new" rear diff and then noticed gear oil all over it and above it. We are assuming the problem may be with the bearings and/or seal. There is some up and down play in the drive shaft. Now we are stuck with a bad rear diff, 70 miles from the mechanic who put it in. We took it to a mechanic here in MA who cleaned the rear diff and checked the gear oil, which was only down about 3/4". There are some small bits of metal in the oil and some noise when driving. Our questions: 1. Do you think it's safe to drive 70 miles to our NY mechanic who put the bad rear diff in? Potentially getting some of our money back or the rear diff fixed for free/cheap. 2. Give up on the one we have and have a mechanic here find and install a different one? 3. If we decide to get a new one: does anyone around the Northeast have a rear diff in good shape that they want to sell? We would be willing to travel max 2 hrs each way. Thanks for the help! I'm with Maris on this one.. Any decent mechanic can replace the defective parts in these rear ends.. Even a shade tree can replace the center section if he is not able to set it up to specs... but to install a rusted housing & putty it up with JB Weld, then zip tie the brake line & THEN CHARGE YOU FOR THIS REPAIR, is beyond my ability to comprehend this type of "repair".... & I'm going to assume that you paid him well to do this? I would NOT try to go back to recoup any $$ from this shop.. Take your losses & move onward.. There are good mechanics & good parts all over the place.... Ask for advice on this forum before jumping in... There are a lot of good people on here & we are all willing to help... I hate to see someone get hammered like this... good luck, donnie Quote Link to comment Share on other sites More sharing options...
fred heath Posted June 13, 2015 Share Posted June 13, 2015 I just changed my rear axle to a gm 14bolt 10.5 ring gear with 4.10.1 gear ratio. My old 5 lug is free for the asking. (1978 GO82). If your close to seacoast NH call Franks Garage at (603) 926-4900. Top shelf mechanics. Quote Link to comment Share on other sites More sharing options...
Pete1122 Posted June 13, 2015 Share Posted June 13, 2015 If you need a new rear diff you should upgrade to 4.56 gearing!! Quote Link to comment Share on other sites More sharing options...
zero Posted June 13, 2015 Share Posted June 13, 2015 I put 4.56 to 1 gears in my 1988 Minicruiser last Fall. Made a HUGE difference. Now I can use 4th OD with the A43D and it cruises nicely most places. One word of caution. One of the popular companies that sells new ring & pinion gear-sets is Yukon Gear. They sell in two grade levels. Do NOT buy the cheaper grade with the lower price for your RV. Those gears have slight imperfections and usually used for off-road trucks and NOT highway cruisers. If you use them (the cheaper ones) - you are likely to get a highspeed "howl" that won't go away no matter how careful you are with the gear setup. Quote Link to comment Share on other sites More sharing options...
thefreedwellers Posted June 13, 2015 Author Share Posted June 13, 2015 Thank you everyone for the advice, especially jdemaris. Some real experts on here! We found a good mechanic close by who was referred to us by another Toyota motorhome owner. Looking to have him pull apart what we have next week and go from there... Quote Link to comment Share on other sites More sharing options...
zero Posted June 13, 2015 Share Posted June 13, 2015 I did not see your photos until now. The rusty replacement looks like a full-floating rear with 6 lug wheels. Is that what your original was? If some so-called "mechanic" replaced a FF original with that rusty assembly - just due to a noise - he ought to be in jail. That rusty rear axle you have now looks just like the one that sat for years in a junkyard in northern NY in a 1983 Sunrader. Junkyard in Sodus NY has rust in the exact same place and the old man (Juliano) wanted $300 for the rear and four wheels. Is that the rear you wound up with? If your original was also a FF with 6 lugs - what happend to it? It is worth some money and whatever noise it was making is irrelvant. Any noise can be fixed. Besides - the entire differential from a 1/2 ton truck and 5 lug wheels is the same as the differential in the 1 ton FF with dual wheels. So used complete differential center-sections are common. Perhaps not always easy fo find one with the 4.10 to 1 ratio though. I know a lot of repair people in central and northern NY. If that's where this awful job was done - who was the criminal who did the work? Quote Link to comment Share on other sites More sharing options...
thefreedwellers Posted June 16, 2015 Author Share Posted June 16, 2015 The mechanic only replaced the center section. That is our original full-floating rear with 6 lug wheels. The replacement came from an assembly with 5 lug wheels, so not the same rear end you are thinking of. We are getting our original differential back and having that one serviced here in MA. Mechanic is in Columbia County... Quote Link to comment Share on other sites More sharing options...
zero Posted June 16, 2015 Share Posted June 16, 2015 The mechanic only replaced the center section. That is our original full-floating rear with 6 lug wheels. The replacement came from an assembly with 5 lug wheels, so not the same rear end you are thinking of. We are getting our original differential back and having that one serviced here in MA. Mechanic is in Columbia County... OK. So the epoxy/JB Weld is on your original axle-housing. I misunderstood. I though the guy you hired (alleged mechanic) had installed something that had to be epoxied. I guess the area where they rust when driven on road-salt is consistent. The one I saw in the 83 Sunrader is rusted in the exact same place. So maybe this new problem wasn't his fault? Very easy to buy a used center-section and find out it makes noise after installing it. That's why I'd never do it unless it came from a rig I knew ran OK. Since you stated the pinion was loose - I wonder if he installed the pinion nut too tight and ruined the bearings. That pinion shaft has what is commonly called a "crush" collar inside. It is made to "crush" when you carefully tighten that nut. It's a cheap mode of assembly at the factory that cuts down on assembly time (instead of using shims which cannot be over-tightened). With the factory crush-collar in place - all it takes it turning that pinion nut a little to far and the bearings are ruined. I've seen it done many times when somebody tried to install a new pinion seal.. Quote Link to comment Share on other sites More sharing options...
thefreedwellers Posted June 19, 2015 Author Share Posted June 19, 2015 OK. So the epoxy/JB Weld is on your original axle-housing. I misunderstood. I though the guy you hired (alleged mechanic) had installed something that had to be epoxied. I guess the area where they rust when driven on road-salt is consistent. The one I saw in the 83 Sunrader is rusted in the exact same place. So maybe this new problem wasn't his fault? Very easy to buy a used center-section and find out it makes noise after installing it. That's why I'd never do it unless it came from a rig I knew ran OK. Since you stated the pinion was loose - I wonder if he installed the pinion nut too tight and ruined the bearings. That pinion shaft has what is commonly called a "crush" collar inside. It is made to "crush" when you carefully tighten that nut. It's a cheap mode of assembly at the factory that cuts down on assembly time (instead of using shims which cannot be over-tightened). With the factory crush-collar in place - all it takes it turning that pinion nut a little to far and the bearings are ruined. I've seen it done many times when somebody tried to install a new pinion seal.. Sorry, I may have used some wrong terms to describe the rear end. What I meant was the center section in the photo is from a junk yard, but the rest of the axle is our original. I talked to the mechanic who did the faulty job and he opened up our original center section, replaced the bearings and seal and delivered it to us for free. We then had our mechanic in MA look it over and put it on the Sunrader and....no noise! We should be all set! Quote Link to comment Share on other sites More sharing options...
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