First off... Truck is an 86' DLX Xtracab 4WD 22R (Aisis carb) 5-speed G54 transmission. All Stock. 190,000 miles.

Problem is that the truck is leaking gear oil from in between where the driveshaft meets the rear t-case/differential??

Another major problem in the same spot is that the dust cover/deflector has came loose... How do you put it back on? I have found the dust cover at Marlin.

 

This thread may be similar to your issue, my truck is a 92'

https://www.yotatech.com/forums/f116...90/index2.html

 

Also there is substantial play when I push and pull the driveshaft, where it goes into the deflection plate... How much is acceptable for spec??? And how exactly to you reinstall that plate(deflector)???

 

Does anyone know how to install pinion seal AND dust deflector????

 

Does anyone know how to install pinion seal AND dust deflector????

 

Are you talking about the output flange on the transfer case? It sounds like you are but you are saying pinion seal and that is down on the differential.

Gear oil coming out right at the driveshaft and not under the the dust shield means you don't have RTV sealant on the splines of the output flange. The dust cover is press fit on the flange, so once you get the flange off just press it back on. There should not be any play on that flange at all. Get the seal from Marlin and replace it and get everything tightened to spec. Anyway here is what you do:

1. Remove driveshaft
2. Do what you can to pry out the punched in section on the output flange nut.
3. Grab a 30mm socket and an impact wrench and spin that nut off. If you can't pry out the punched-in section don't worry about it. The impact gun will overcome this and the nut is much softer than the output so you won't bugger the threads up.
4. Remove the nut, the thick washer, and get your flange off. Pull the seal out with a seal puller, and clean splines on the output shaft and the flange up as best you can.
5. Grease the sealing surface of the new seal, get it started going in the tcase and then pound it in with a big socket or something
6. Get some ultra grey RTV, put a decent amount on the splines of the inside of the output flange. Put some grease on the sealing surface of the flange and carefully put it in.
7. Fill up the gap in the splines with RTV, then put more RTV on the inside surface of the washer. Push the washer on there and you want to see a good amount of RTV come out once you start spinning the nut back on.
8. DO NOT SKIP THE RTV! It will leak without this.
9. Retighten the nut to 90 ft pounds and stake it.
10. Put your DS back on and let the thing sit overnight before you drive it again.

 

 

The shaft on the output flange, going into the dropout case, is wobbling. Approximately 1/8-1/4. It's also spraying gear oil. I drove it about 1-2 mile after I heard the deflector rattle. Is it safe to drive it to the shop??

 

Thanks for the step by step instructions also. Am I needing with the preload? Do I need to measure it after?

 

Thanks for the step by step instructions also. Am I needing with the preload? Do I need to measure it after?

 

Will Toyota FIPG work instead of FTV? Do I need medium strength locktite for the threads?

 

Toyota FIPG will work, I think they recommend the orange version for the t-case.

So, it sounds like you have issues at BOTH the t-case and the pinion?

Yes you are supposed to set preload on the pinion bearing with the torque you put on the pinion nut. I have never done that so I can't comment. I have replaced the pinion seal without worrying about preload, I just tightened the nut back to where it was staked before. It was a lot of torque, comparable to the amount on the tcase flange. You could just take the DS off and tighten that pinion nut down. I doubt you would do any more damage than has already been done by running it with play.

 

I'm not willing to do this job half right. I want everything done exactly to factory spec with OEM parts. Not worrying about preload doesn't seem like a great idea. And I have not drove the truck since the deflector came loose and I noticed there was a problem. Drove less than a mile after I noticed, and it was at 15mph, just to get it somewhere I could work on it.

 

If you want it to be perfect, the 3rd member would have to be removed from the truck and overhauled using new bearings and crush sleeve.

Your truck has near a quarter million miles on it, and this is not a perfect world. You may well be able to change the pinion seal, and then retighten the pinion nut until all play has been removed, and then just a little more.

This might enable you to get some more service from your differential, and it might not. You really have nothing to lose be trying, because if it fails, the same overhaul of the 3rd member would be required anyway.

You can tighten the pinion nut to 120-130 foot pounds without changing any existing pre-load, and take it from there.

 

Missed that part. No you do not and should not use locktite at all on these threads. The nuts are staked and that keeps them from turning. You will see this when you remove the driveshaft and look at the nut. It will make sense.

Have to agree with millball that you needn't be too concerned with the pinion. In fact, i would guess that you will be able to see where the proper torque should be based on where the nut was staked and where the the divot is that the nut gets pushed to. It is very high torque on that nut, and my guess is someone in the past loosened it, probably to change the seal, and just tightened it to where they thought it was enough. Hack job and now it's loose again.

I remember someone talkng about replacing a pinion seal, and how you were "supposed" to be sure to reset bearing preload, but instead you just tighten the nut back to where the staked part of the nut and the divot on the output shaft line up, and there you are. Close enough, and it takes A LOT of force to get it there. I have done it twice with no issues at all to the third member.

 

Also, pinion bearings make noise for a long time before they give up the ghost. It isn't going to just explode out of nowhere and leave you stranded.

Also, your exact problem is still confusing. Let's call them "t-case flange" and "pinion flange." Pinion is connected to your differential. Which is wobbling? Which is spraying oil?

 

Took it to a shop today and they said there was too much play in the shaft going into the third member. I'm calling thi the pinion flange ( it bolts to the u-joint and has a shaft going into the dropout case(third member housing)

Not sure if the really know what they're talking about from he advice I'm getting on here.

Something is definitely has to be done before driving it anymore though. It makes a horrible sound when the clutch is pushed in and the truck is rolling. In gear it's not nearly as bad and make very little noise.

what would be the cheapest, best, reliable route? Any advice?

I want to keep everything stock. Looked at Marlin but it doesn't look like the make a complete rear diff with stock 4.10 gears?

 

Going to tighten that pinion nut in the morning and see if anything improves. I'll take pics and post. Still plan on ordering a new or used complete differential after the weekend. Then try to rebuild the old one on my own. I've never attempted a job so complex.

 

If you intend buying a commercially rebuilt 3rd member and have it installed by a shop, you'll likely pay upwards of a thousand dollars.

There is also the possibility of installing another used 3rd member that might be got from a wrecking yard, or somewhere like craigslist, or maybe even from a member here. 4.10s' are pretty common.

You have good advice in front of you that might well permit you to get substantial additional service from what you've for less than 20 dollars for a pinion seal and a couple hours of your time.

If the repair we have previously outlined fails;. worst case,.you are merely back to you commercial parts and labor costs.

 

Dropped the driveshaft and the pinion but was really loose. Tightened it up but can't get it to where it was previously staked. And advice? Impact? Or just tighten with a torque wrench?