cnmrosko

I'm planning to replace my rear differential oil seal, the pinion bearing shaft crush sleeve and resetting the pinion nut pre-load. Can someone tell me if the pinion bearing pre-load can be reliably set without dropping the differential or removing the axles from the differential? If the axles stay in does this have much of an effect on the pinion shaft pre-load?

Thanks.

GSGALLANT

You can do it with the 3rd member installed, but it's a bit tricky to get accurate. You have to measure pre-load within the backlash of your gears. That is... when you rotate the pinion back and forth by a few degrees, you feel the "click...click...click" when your pinion gear touches the ring gear. So you can actually rotate the pinion back and forth a couple of degrees without the pinion gear touching the ring gear. That is where you have to measure pinion preload.

Keeping in mind that you want to measure the rotational force required to keep the pinion turning (and not the force required to start the pinion turning, which is higher), you can see that it will be very hard to get an accurate measurement of pinion pre-load with the 3rd member installed.

86tuning

Unfortunately, the answer to this question is:

If you have to ask, the answer is no.

For your first one, you should plan to spend a whole day, and take the whole thing apart. After that, if you feel confident, you can do your buddy's truck 'on the car' but hey, it's not your truck....

cnmrosko

Thanks.

Apparently the proper procedure is pretty complicated for replacing the pinion flange oil seal!

According to my Toyota service manual once the pinion flange nut is loosened the pinion shaft crush collar must be replaced and the bearing pre-load must be reset when replacing the pinion flange nut.

When I called the local Toyota Service department and asked what the labor charge was for replacing the pinion shaft oil seal they said it was 1 hour & 45 minutes?



Now I'm thinking, I'll drop the differential and take it to a Toyota tech to have the crush collar and oil seal replaced and have them also check the other gear tolerances.

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cnmrosko

Well...

I dropped the differential and took it to a local Toyota shop and the shop foreman tells me that the differential has to be mounted on the truck for them to replace the oil seal and pinion crush sleeve, and, that they are not set up to work on the differential on a bench. It seems that they also are not set up to properly inspect a differential. Strange... my Toyota shop manual shows all of the differential work as being done on a bench.

He told me that when customers have problems with their differentials they often just order a whole new differential unit or rear end. He also told me that I may have ruined my gears by driving with the pinion nut not being torqued tight enough.

I asked how they replace oil seals and he told me they just mark the place of the old nut on the pinion flange and count the threads and tighten a new pinion flange nut to just a little past those marks. He also told me he uses an impact gun.

Can anyone recommend a tech in N.E. Ohio or N.W. Pa. who knows how to properly inspect, service and or set up Toyota differentials?

Thanks

GSGALLANT

Yeah... just when you think you are safe to bring your vehicle to a dealership to get the work done, you realize that there are many backyard mechanics around that are setup better than they are.

Right... because my pinion seal is leaking, please order a new differential for me... what are they smoking at that dealership?

Between my friend and I, we made all the special service tools that are required to properly rebuild a differential... including a mount to secure the differential to our workbench.

Look around... I'm sure you'll find somebody local that's qualified to do the work.

toy_tek

My best friend has a shop in Columbus, and gets up to Valley City / Medina county pretty regularly. Although he's out at Sturgis right now... not sure if thats really going to help you or not. He can do it for you, if you aren't in a rush. PM if that will help you at all.

cnmrosko

Can someone verify if I've got this right?
Rear Differential , "Total" pinion nut pre-load with all used bearings & gears should be approx. 8 ftlb. to 14 ft.lb?

(98 4wd 4-runner stock 410 differential)
http://personal.utulsa.edu/~nathan-b...35differen.pdf

GSGALLANT

Watch your units. Pinion preload is in in-lbs and not ft-lbs. If you tighten that sucker to 8 to 14 ft-lbs, you'll be smoking your bearings pretty quick.

cnmrosko

Ouch, thanks for the reminder.

I couldn't find a low range inch pounds torque wrench anywhere locally. I ordered one online.

I thought someone here might be interested in seeing my custom carrier bearing torque tool, see pics. Cost me about $4.00. It fits perfect, the nut threads even "snap" into place.







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GSGALLANT

Nice tool design. It should certainly be strong enough.