Speedometer issue

[RHS]

I bought '82 Sunrader 18' w/upgraded rear axle. The seller said had originally had 5 spd trans went bad was replaced by 4 spd. My issue: the speedometer said 75 plus when I was doing 55 plus. I am not sure how to find trans model #. I am not sure axle ratio. I am guessing speedo gear, dealer needs model# of trans. Has anyone run into this?

[zero]

I've run into that problem on many trucks and cars - not specifically on a Toyota. Incorrect tire size, rear axle swap, incorrect speedo gears in the trans all can cause the speedometer error.

You need to ascertain what the rear axle ratio is. 4.1 to 1 or 3.9 to 1 is the most commom in RVs but there are many other possibilities.
Then you need exact tire size.

Then you need to get the speedo gears that match your axle-ratio and tire diameter. Toyota has charts for it. There are two gears in the trans for the speedo drive. Sometimes you can replace just the one "driven" gear at the end of the speedo cable (easy fix) but with some changes it requires changing both gears including the one inside the transmission 'drive gear". I assume your trans is the L43 or something like that. Easy to tell by it's outside appearance. Take a photo and post if your dealer doesn't know.

Just changing the one "driven" gear is the cheapest and easy fix - if possible. If not - you can tear the trans apart to change the "drive" gear.

Or for around $75 you can buy a correction-gearbox. It's a tiny little gear box that goes between the end of your speedo cable and transmission. They get custom assembled to your needs. I've used them in two trucks to get the speedos corrected. Obviously this only applies to mechanical speedos and not electric.

[zero]

I bought '82 Sunrader 18' w/upgraded rear axle. The seller said had originally had 5 spd trans went bad was replaced by 4 spd. My issue: the speedometer said 75 plus when I was doing 55 plus. I am not sure how to find trans model #. I am not sure axle ratio. I am guessing speedo gear, dealer needs model# of trans. Has anyone run into this?

I forgot to ask. Is your Sunrader a Toyota or Nissan? At some point in time Sunraders were offered with Nissan platforms and 5 speed manual trans. All the paper work I've seen for Toyota Sunraders show 4 speed only for manual.

[zero]

Some specs:

If you have the 185R-14" 6 ply tires and a 4.1 to 1 rear axle ratio . .

If the trans has a 10 tooth drive gear - your cable needs a 32 tooth driven gear
If the trans has an 11 tooth drive gear - your cable needs a 35 or 36 tooth driven gear

Same tires with a 3.9 to 1 rear axle . .
10 tooth trans gear needs a 31 tooth driven gear
11 tooth trans gear needs a 34 tooth driven gear.

Here are some common gear sets in Toyota trucks . .

part # 33403-39345 31 tooth, 31x11 RN131
part # 33403-39425 32 tooth, 32x11 RN101/RN110/RN13
part # 33403-39415 33 tooth, 33x11 VZN10*/VZN110/VZN13*
part # 33403-29315 32 tooth, 32x10 RN101/RN110/RN13

[zero]

I bought '82 Sunrader 18' w/upgraded rear axle. The seller said had originally had 5 spd trans went bad was replaced by 4 spd. My issue: the speedometer said 75 plus when I was doing 55 plus. I am not sure how to find trans model #. I am not sure axle ratio. I am guessing speedo gear, dealer needs model# of trans. Has anyone run into this?

Speedo gears are the same regardless if 4 speed or 5 speed. The gear set used goes by tire-diameter and rear axle ratio. You an easily determine rear axle ratio by jacking one rear wheel off the ground, put trans in neutral, then turn the driveshaft and see how many turns it goes to make the wheel turn once. If the driveshaft turns just a hair over two turns to make the wheel turn once - you've got a 4.1 to 1 rear axle ratio. If it a hair under two turns to make the wheel turn once, you've got a 3.9 to 1 rear axle ratio. If the driveshaft turns 1 1/8th turns you've got a 4.30 rear axle ratio, etc.

Then you can pull the speedo-gear assembly out from the trans (where the cable hooks up) and peek in with a flashlight. You can see the drive gear inside and the tooth count wil be marked on it. Then you have the info to calculate what driven gear you need to order.

[RHS]

Thanks for all the info. It is a toyota w/185R14 tires. The driven gear has 28 teeth I think it is 4.1 rear end.

[Derek up North]

I'm far from an expert (and have no wish to become one) but I think that it was only in the '70s that 3.90:1 was supplied in Toyota MH and then only with (a rarely fitted) automatic. 4-speeds came with 4.10:1.

Things settled down to make the 4.10:1 standard issue until the '90s when some manufacturers (mostly Winnebago, it seems) started offering 4.30:1 with the V6 automatic.

[zero]

I'm far from an expert (and have no wish to become one) but I think that it was only in the '70s that 3.90:1 was supplied in Toyota MH and then only with (a rarely fitted) automatic. 4-speeds came with 4.10:1.

Things settled down to make the 4.10:1 standard issue until the '90s when some manufacturers (mostly Winnebago, it seems) started offering 4.30:1 with the V6 automatic.

Late 80s 20 foot Winnebago shows a 3.9 rear axle ratio with the 2.4 engine and auto-OD trans.

[linda s]

Late 80s 20 foot Winnebago shows a 3.9 rear axle ratio with the 2.4 engine and auto-OD trans.

Shows it where. We did a casual survey on the toyota-campers site and no one had a 3.9 ratio. Most had 4.1 and a few like Derek had a 4.3.

Linda S

By the way quite a few toyota-campers member have bought speedometer ratio adapters from this place with good results. Don't have to go there they shipped them. Just need to let them know the model vehicle and how much the speedo is off.

https://plus.google.com/103811379957440758304/about?gl=us&hl=en#103811379957440758304/about?gl=us&hl=en

[zero]

Shows it where. We did a casual survey on the toyota-campers site and no one had a 3.9 ratio. Most had 4.1 and a few like Derek had a 4.3.

Linda S

By the way quite a few toyota-campers member have bought speedometer ratio adapters from this place with good results. Don't have to go there they shipped them. Just need to let them know the model vehicle and how much the speedo is off.

https://plus.google.com/103811379957440758304/about?gl=us&hl=en#103811379957440758304/about?gl=us&hl=en

Shows it in the Winnebago brochure but there is no date marked on it, although there are many photographs. It shows a 2.4 engine and looks like an 88 or 89 truck. 3.9 rear axle ratio and automatic trans with OD, and a 20.7 foot RV. I'll post it later when I'm on the computer where I have the PDF stored.

RE: RHS and your speedo problem. I just looked at the gear set in another Toyo RV I have (1981) with a 4.1 rear and four-speed trans. I know the speedo worked well in it and seemed to be accurate with the 185R-14" tires. The drive gear on the trans has 6 teeth (seems to the standard). The driven gear where the cable hooks to has 19 teeth. A new one from Toyota or whoever is Toyota part # 3348239025. May be all you need.

[waiter]

I've been following this thread, last time i messed with speedometer gears was back in the 60's. Anyway. If I had this problem, this is what I would do.

1) Climb under the truck and remove the Speedo cable from the tranny,

2) There is a keeper bolt that holds the speedo gear shaft gear thing in (the speedo cable screws into this) remove that bolt and the metal retaining clip.

3) The speedo gear shaft should pull straight out, (may need to reconnect the speedo cable to it so you have something to pull with). Have a small pan or towel ready, because it might drip.

4) Take that to the Toyota Dealer.

Count the teeth on the gear, you want one with a couple more teeth. ( you need the speedo to turn slower) Ods are very good that they only have one or two to select from.

I thought I seen on line where this assembly runs about $20.

Good luck

John Mc

88 Dolphin 4 Auto

[zero]

By the way quite a few toyota-campers member have bought speedometer ratio adapters from this place with good results. Don't have to go there they shipped them. Just need to let them know the model vehicle and how much the speedo is off.

https://plus.google.com/103811379957440758304/about?gl=us&hl=en#103811379957440758304/about?gl=us&hl=en

Do they make their own gearboxes or are they reselling the ones that I posted about earlier that are made in Michigan. I ask becaues most places I came across who sell them are buying them from the place and Michigan and tacking on extra dollars to the price. The company that makes them (that I've referred to) sells direct to anyone and is cheaper -when compared to their own product resold elsewhere. I found that out when the OEM unit in my Dodge truck went back and Dodge wanted over $100 for a new one. I then found the same at several transmission specialists for $90, and finally tracked down the company that makes them. Direct my new one was $62.

"Clark Brothers Instrument Company stands alone as the largest single supplier of gear ratio adapters to Original Equipment Manufacturers in the United States. All of our ratio adapters meet or exceed the strict quality requirements demanded by these companies. Our customers, both large and small, benefit from the competitive pricing made possible by high volume"

56680 Mound Rd | Shelby Township, MI 48316 USA | Tel: 586-781-7000 | Fax:586-781-7005 | Email: info@clarkbrothers.net

http://www.clarkbrothers.net/ratio_adapters.html

[zero]

.Count the teeth on the gear, you want one with a couple more teeth. ( you need the speedo to turn slower) Ods are very good that they only have one or two to select from.

I thought I seen on line where this assembly runs about $20.

Good luck

John Mc

88 Dolphin 4 Auto

The problem is not all driven gears can be used with all drive gears. He says he's got a 28 tooth when the standard gear in that year Toyota with a 4.1 rear would have 19 teeth - so something is screwey. He might have a trans out of car with a very different drive gear inside. The only speedo driven gears used in the older trucks were 17, 18, or 19 teeth (the gear on the outside). Cars have gears with 28 to 35 teeth but also use a different drive gear inside the trans. The trans has to come out and be torn apart to change it. I doubt you're going to find a dealer that can tell you what mix of gears can be swapped into a an unknown year and model trans that was swapped into a truck with a swapped-in rear axle also of undermined ratio. If he knew what the model trans was including year and original application it would make a big difference.

Here are all the driven gears used in Toyota trucks 1969-1992 (that I am aware of).

GEAR,DRIVEN N=18; N=18,MARK 18:6,N=18; N=18,MARK:18X6; W/ER78 OR P195/75R14 TIRE,N=18; W/ER78-14 TIRE,N=18 1969-1988 # 3340369065

GEAR SUB-ASSY, SPEEDOMETER DRIVEN (ATM); GEAR SUB-ASSY, SPEEDOMETER DRIVEN (MTM).

1983 TOYOTA PICKUP 2400CC, MANUAL , 4-SPEED and 5-SPEED

GEAR N=18; N=18,MARK 18:6; N=18,MARK 18:6,N=18 1981-1992 # 3348239135

GEAR SUB-ASSY, SPEEDOMETER DRIVEN (ATM); GEAR SUB-ASSY, SPEEDOMETER DRIVEN (MTM).

1983 TOYOTA PICKUP 2400CC, MANUAL , 4-SPEED and 5-SPEED

GEAR N=19; N=19,MARK 19:6; N=19,MARK 19:6,N=19 1980-1988 # 3348239025

GEAR SUB-ASSY, SPEEDOMETER DRIVEN (MTM).

1983 TOYOTA PICKUP 2400CC, MANUAL , 4-SPEED and 5-SPEED

GEAR N=17,N=17; N=17,N=17,W/7.00-14-6 TIRE 1980-87 # 3348239065

[linda s]

Yes I found the brochure with the 3.9 ratio listed too. Funny but no one I have ever heard of actually claimed to have one including Winnebago owners. Went back quite a few years on the toyota-campers site and the only one mentioning it was me cause thats what car-parts says they were. I've said before a friend of mine bought one of those supposedly 3.9 axles for his 4x4 Sunrader after going to the wrecking yard and confirming it was actually the 4.1 that he needed. Would be nice if any Winnebago owners could check their tag under the hoods and see what they have. Looking for G542 axle code of the 3.9 instead of G292 of the 4.1

Linda S

[zero]

Yes I found the brochure with the 3.9 ratio listed too. Funny but no one I have ever heard of actually claimed to have one including Winnebago owners. Went back quite a few years on the toyota-campers site and the only one mentioning it was me cause thats what car-parts says they were. I've said before a friend of mine bought one of those supposedly 3.9 axles for his 4x4 Sunrader after going to the wrecking yard and confirming it was actually the 4.1 that he needed. Would be nice if any Winnebago owners could check their tag under the hoods and see what they have. Looking for G542 axle code of the 3.9 instead of G292 of the 4.1

Linda S

The axle code works OK when an RV is original. Doesn't do much good if something has been swapped in, upgraded, etc. Add to that the fact that any 1/2 ton ring-and-pinion of many ratios can be bolted into the dually 1 ton rear axle assembly -and it could be near anything. I just installed my original 1/2 ton ring and pinion from my Chinook into my 1987 dually 1 ton rear axle as one examply. In my case -even though both assemblies had different amounts of gear teeth - the overall ratios are 4.1 to 1 on both. My 1978 ring&pinion assembly has 9 teeth against 37 teeth. That is a 4.1111111 to 1 ratio. My 1987 ring&pinion assembly has 10 teeth against 41 teeth. That is a 4.1 to 1 ratio.

The only easy way to know for sure is to jack up one wheel, turn the driveshaft and count. If the driveshaft turns twice to every one turn of one wheel - it's a 4.10 to 1. And if apart, count the gear teeth. Or if you've got a tach - figure by overall gear ratio, RPMs of engine, speed, and tire diameter.

Here's what the original speedo gears look like in 4 and 5 "short" five speeds used in the late 70s and early 80s Toyotas.

[linda s]

Well I was just wondering if any Winnebago owners could check and see if they have the 3.9 axle. Would be interesting to find some out there. Winnebago's were only made from 86 and up so they would not have needed an axle upgrade. Tag should tell the real ratio unless they switched out the gearing.

Linda S

[RHS]

You guys a so helpful. Thank you. The trans is not the L43 (I have a '77 with that trans) I have an '83 out in snow bank that has the 19 tooth one. Looking at the drawings in the haynes manual it looks like the one I am working on is maybe a W42,46,50 etc. The one with the 19 tooth looks like it maybe an L45,48. While at wrecking yard looking for something else I saw an '85 half ton with same trans & 28 tooth gear do not know what rear end it had. If it had 3.9 would there be that much difference (the one at wrecking yard)?

[waiter]

RHS, Did you say that you did remove the gear and it was a 28? a 35/28 ratio matches the 75/55 speed difference that you reported. What I'm saying, a 35 gear would slow the speedometer down and it would be reasonably close. but as JD points out, these are often matched sets, you can't change just the speedo gear, you usually need to change the driving gear also.

JOhn Mc

88 Dolphin 4 Auto

[waiter]

Here is something that you might be interested in, but I think this is backwards of what you would need i.e. for every one turn on the input shaft, , you probably want 3/4 turn on the output.

Speedometer Adapter

Here is one that looks pretty close

reduce 27%

While your on e-bay, you might search for Speedometer reducer and see what you come up with.

John Mc

88 Dolphin 4 Auto

[zero]

Here is something that you might be interested in, but I think this is backwards of what you would need i.e. for every one turn on the input shaft, , you probably want 3/4 turn on the output.

Speedometer Adapter

Here is one that looks pretty close

reduce 27%

While your on e-bay, you might search for Speedometer reducer and see what you come up with.

John Mc

88 Dolphin 4 Auto

The company that makes those adapters offers them in any reduction ratio. You just give them the % reduction (or increase) needed and they install the gears to match.

[Maineah]

1/2 ton pickup had the 3.90 rear.

[Maineah]

Some older US cars/trucks had eccentric driven gear housings allowing you to offset for a larger gear but the Toyota does not unless you get an outboard gear box you’re going to have to pull the tail stock and change the driven gear as well. Hard telling what your trans came out of.

[zero]

You guys a so helpful. Thank you. The trans is not the L43 (I have a '77 with that trans) I have an '83 out in snow bank that has the 19 tooth one. Looking at the drawings in the haynes manual it looks like the one I am working on is maybe a W42,46,50 etc. The one with the 19 tooth looks like it maybe an L45,48. While at wrecking yard looking for something else I saw an '85 half ton with same trans & 28 tooth gear do not know what rear end it had. If it had 3.9 would there be that much difference (the one at wrecking yard)?

W50 usually has the same speedo gear setup as the L-series four speed. When looking underneath, does it look like a new hole was cut for the shifter to fit in? The only truck-type transmssions that fit the older trucks are the L42, L43, L45, L50, L52 and W50. The W55, W56, G52, G54, etc. are longer and won't fit without a new hole cut in the floor and the driveshaft shortened. There are a few short car-only transmissions.

[RHS]

Thanks again the hole in the floor was moved back farther. Could this be a G40?

[zero]

Thanks again the hole in the floor was moved back farther. Could this be a G40?

G40 would be my guess. I think it is the only "long" 25 1/2" four speed transmission used in trucks. Your truck originally had a 21" long trans so the driveshaft was probably shortened by 4 1/2" and the hole for the shifter relocated. There are other four speeds but they are older and short (L40, L42, L43, L45, T40, W40, W42, and W45). The newest "W" series I know of what the W45 four speed used in some 1981 trucks and it's a short trans.

[RHS]

Update:I contacted clark brothers they sent me to another company that said they did not do toyotas. contacted comercial speedometers (the one Linda suggested) they said they would make it & ship the same day $94 including shipping. Thanks for all the help what would we do without you guys & gals.

Rich