Diff pinion oil seals 94' HDJ80 1HD-T

[bushpig]

I've been really fascinated by some old postings about replacing diff pinion oil seals
and setting the backlash preload. The advice given by quite a few guys was so good that I just had to sign up.
I've done all the maintenance and repair work on my truck since new and always used the factory shop manual.
I'm getting ready to replace both the front and rear diff pinion oil seals and was pondering the following:
If my diffs are in really good shape, do I have to remove and replace all the components specified in the manual? Why can't I just replace the seals?
One guy advised that to save all the hassle of buying an inch/pound torque tool, the pinion nut should be carefully marked before removing and then replaced to exactly the same spot, if only the seal was going to be replaced. This seems to make sense.
Any new ideas out there or any additional info before I start?

The old bushpig.

Quote: If blood isn't flowing, you're not concentrating.

 

[Gold Finger]

Welcome aboard, there is a growing band of diesel 80’s here now, mainly petrol here though the chassis details are much the same. I can not help you my self but there should be a few more coming on line later when they wake up though Saturday is not the busiest day on here. I think I saw your thread on 80’s cool. It is always useful to give vehicle details and as much other information to enable people to diagnose and advise I think your vehicle is the same as mine a 1994 HDJ80 1HD-T. There is a search function on this board which may give the information that you require. A photograph of your rig may also go down very well as diesels or rare that side of the pond. How long have you had it and what is the mileage any modifications etc? Good luck with your request.

 

[bushpig]

Thanks for the welcome Goldfinger. I did do a post on 80s cool and that was where I got some excellent advice from Greg. The posts on IH8 MUD are very detailed, with photos and part numbers, and that is why I decided to see if there are any new revelations.
I bought my 94' VX Turbo Diesel new. It has factory dual batteries and I've done quite a few mods: OME heavy duty springs + 10mm spacers + castor kit, additional 175litre tank, custom front bumper + Ramsey 8000 winch, Safari snorkel, 285x75x16 BF Goodrich AT tyres, Engel 60litre fridge, Engel 13litre freezer and Backrack spare wheel carrier. I've done 94000 miles with no trouble at all until these pinion seals.
How do I go about including a photo?

 

[robbie]

Good day Bushpig. As for the pinion seals Yes you can do them on the truck. Yes the describ method is OK, the i do prefer the inch lb torque wrech over it, but it takes knowing what you are trying to get to that matters. If you have high milage, say over 120k miles then you may want a little more tightening on the nut to create more preload. The preload loosens up over time due to wear. If I remember right new factory is around 17 INLBS where older bearings need something around 10-12 INLBs, This may be hard to get right as to the use of the torque wrench is hard to make right as you turn all the other stuff with out taking it apart (the ring gear, axles etc). So if you have lots of miles on the truck, a feel method is sometime used. Feel the tension and make it a little tighter then before, by taking the nut to the same place and then tighten it more in little bits, to make the bearing tension a little bit tighter. But be careful not to create binding of a the bearing, if so you will need to back the nut off and try to bring it up again with less tension. it may help you to have a friend that has done this a time or to too help you with the first one, then you will have a better feel for it. If by grabing the current drive flange at the pinion and it moves up and down or side to side, you may have some bad bearings any how and they may need to be replaced, Or if they feel rough when turning(pitting, scruffing etc), they will need to be replaced. I reread some thing and you have gotton good advice from greg g, I would think following what he and others have said is good enough. What do some American's know any hooo. Good luck later robbie

 

[Gold Finger]

To attach a photograph, go to the bottom of the page and click advanced then scroll down the page until you hit manage files click on that and it will bring up you files and take it from there I have never posted a photo so I am guessing. With all those cooler arrangements I guess we would be OK for a cool beer . Sounds like you have your vehicle sorted for trips out and about.

 

[bushpig]

I tried to attach a couple of JPEG'S but when uploading, a message in the window stated "no information in the document"
Can anyone tell me what I'm doing wrong?

 

[bushpig]

A very good morning to you Robbie & thanks for all the good advice. I feel confident that with all the excellent info given by you & Greg G, I can now go ahead & tackle this job. As you say, I'll make sure that there is no excessive wear on the bearing etc., and if there is, I'd rather go the whole hog and replace the parts that are worn. I think it will be worthwhile to borrow or buy an inch/lb. torque wrench to make sure that the job has been done properly.
On an old post on this site there was some good stuff regarding the torque measurements.
The torque of the nut should not be confused with the backlash torque of the freeplay between the teeth of the pinion & the teeth of the ringear.
I understand this to mean that the nut should be torqued a bit at a time with the big old torque wrench, & then the backlash torque should be measured with the little torque wrench. The backlash measurement should be taken without moving the ring gear & axles as it is only the freeplay between the teeth that has to be measured.
Is this correct?

Many thanks
Bushpig

 

[robbie]

Your asumptions on how to torque the nut and then read the little wrench is correct. This can be difficult as the back lash is rather small, so you only have a little room to measure the bearing preload(patientence is required). If you have to error, error on the loose side of the attempt at getting it right. If you tighten it too much, and back the nut off a hammer tap on the end will loosen the bearing back up. If tightened it way too much and have to back it off, there is a chance that the crush collar can be crushed too much and will cause accelerated wear. Good luck, if you have more questions post them up. later robbie

 

[bushpig]

Thanks Robbie, everything is now clear as hell

All the best, Bushpig