[Bazuka]

I have brought a diff rebuild kit with 2 side gear bearings, 2 pinion bearings, an oil seal and the crush sleeve and want to rebuild the front diff. I could not find any forum pages or articles of someone doing a diff rebuild so I have a few questions before I start...

Thrust play, bearing pre-load and gear backlash all look daunting but simple enough to work out and I am keen to take my time and learn but shimming the pinion properly scares me and the special tool (bevel pinion mounting dummy) used in the manual is worth a lot more than I want to spend.

So my question is can I replace the two side bearings and the two pinion bearings without needing to re-shim the pinion?

If I have to re-shim, does anyone know where I could hire the bevel pinion mounting dummy (09926-78310)?

Hamish.

[tanshi]

in all honesty, if you need to ask these questions you shouldnt be rebuilding a diff. Its a complicated thing to do right.
a simple set of instructions from the internet will have you rebuilding it again in 2-3 months

[HarryHoudini]

I agree,went thru the same dilemma when specialist Diff. places wanted $400+ to rebuild my Diff.Its a specialist job thats hard to get right and with a Suzy. diff you need it close to factory specs. if your going offroad.,very easy to strip pinon or crown gears.
After saying that i think there is someone on this Forum that rebuilds Diffs. for his mates.

[droverdave]

Doesnt the factory service manual give good instructions on how to do it? I was browsing through it the other day and it looked good.

I'd get the maunal out, and then read as much as you can about setting up differentials. it does look quite complicated, and i suspect the problem may end up being the lack of equipment at home. It is a tedious job but nothign stopping someone from doing a tedious job at home i they understand it.

But certainly read as much about it as possible before making a decision to DIY or get a shop to do it.

I think if you are asking these questions than you are thinking about the job, which is certainly a good start.

This is an interseting read to get you started. http://www.differentials.com/technical- ... structions

[jono165]

Rebuilding a diff is pretty complex and there's a degree of experience required also.

If it was just installing a minispool or lockright id say by all means do it yourself, you can count the turn of the adjusters and mark everything so it goes back together the same.

You would need to spend up on tools to do a rebuild properly, last time I looked a quality dial guage and in/lbs micrometer torque wrench weren't cheap.

I believe the pinion shims are matched to the housing/gearset so you might not need to change them, I'd also be investigating getting a solid pinion spacer made up if you are running big tyres/locker.

[Bazuka]

I have read the factory service manual and much information as I can find online about suzuki diffs and I agree it looks complicated but I have all the time in the world and I would like to learn how to do it. I can see that it is a lot more fiddly than most other jobs on a suzuki and I can see how most people could not be bothered or would not have the time to do it right but I am in the process of rebuilding most other components on the suzuki and I don't want to leave the diffs out. At minimum I would like to change the bearings and check for wear on some of the key parts.

The only thing I don't like the look of is shimming the pinion using a $500 special tool that the manual said I need. I read on another forum that if rebuilding a suzuki diff but not changing out the pinion gear then it should not need to be re-shimmed. So I was really just asking to confirm this...

Worst case scenario I have to find a replacement front diff head and that is not the end of the world for me.

Thanks droverdave for the link, time to do more reading.

[droverdave]

You could just ring a differential shop and ask them? Most places are keen to have a quick chat and give advice.

My instinct tells me that if you remove either one of the gears for any reason, then you'd pretty much want to set it all up from scratch again if for nothing else a quality assurance on the diff.

[Virt]

Have you thought about just putting a locker in instead? (if you'd make use of it of course)
I know you already have the rebuild kit but as others have said locker is not too hard to DIY, rebuild can be a nightmare, for the potential cost of buggering it up and/or paying a pro $400 to do it, I dare say you could get yourself a Lockright or Spartan?

[tanshi]

how is a locker going to help. you still need to rebuild if you do that any way

[Virt]

tanshi wrote:

how is a locker going to help. you still need to rebuild if you do that any way

I wouldn't call it rebuilding and it's a bit easier than an actual rebuild IMO.

[tanshi]

if you do a half assed job your right. but if he has the rebuild kit and as stated above wants to rebuild the diff. your input to add a locker doesnt help him in the slightest

[JrZook]

Virt wrote:

tanshi wrote:

how is a locker going to help. you still need to rebuild if you do that any way

I wouldn't call it rebuilding and it's a bit easier than an actual rebuild IMO.

WTF? He is asking about rebuilding a diff, not installing a locker into it.... Yea a locker might be easier to install but so if putting air in the tires, irrelevant tho.

To replace all the bearings and then reassemble the diff and set it up again is a bloody pain in the butt! Trying to get a proper meshing pattern on the R&P can be very frustrating and if not done right will end up in tears.

I had to have two attempts on one of mine. New bearings/seals etc, had a really nice pattern on the R&P. Threw it in and it was dead quiet for the first few 100ks then got noisy again on coast. Something must have bed in or shifted. Luckily no damage. After a readjustment to regain the pattern it worked out.

If you have the time and equipment (as well as patience) go for it. Just be prepared to replace the whole center if it goes horribly wrong.

[Virt]

Fuck sake, I was just suggesting an option...
Whatever.

[tanshi]

oh in that case cool. Fit some transfer case gears Bazuka, will totally help with the rebuild of your diffs

[31zook]

If you take your time, work at it as you go and understand that it might need to be re-done, then go for it!

The pinion shimming tool isn't needed, you will just have to have the diff almost fully assembaled before you check tooth contact. This is time consuming and a business can justify $500 over 10 diffs to save a bit of time.

Good quality tools will help also, plus once you have done the job you still have a dial indicator and a torque wrench.

[Gwagensteve]

Bazuka,
Good on you for wanting to have a go at this job, but does it need to be done? If the pinion is tight and the seal isn't leaking I think I'd go to almost any length to avoid having to touch it.

I've seen enough "professional" gear setups were the contact patch is wonky or the pinion goes loose to try to avoid pinion work on a Sierra diff unless it was 100% necessary.

Steve.

[Bazuka]

Does it need to be done? I don't know, I have not driven it... How often should they be done? 100K? 200k? Just when they need it? I would be surprised if this zook has ever had it's diffs opened and it has 280k on the clock.

I am currently unemployed and have nothing better to do than rebuild an old zook. Time is on my side and I am a patient person hence why I am talking and getting ideas from you nice people before I start. I don't mind taking it apart and putting it back together as many times as it needs it. And even after the first week or two weeks or month just to check the tooth pattern after the bearings have settled.

Diff lock is not something I am considering as the zook is for light-ish 4x4ing and daily driving.

The tooth contact pattern can tell you correct pinion shim? I see... The manual describes this after they uses the special tool so guess work, then put it all back together and check tooth contact and take it apart readjust etc till it is right is they way to go.

I am prepared to replace the whole center if I have to so I am going to give it a go.

[Gwagensteve]

I'd leave it alone and do it if it needs it. There's no service interval. If the diff is quiet and doesn't leak from the pinion leave it alone IMHO. They're too easy to stuff up to pull apart for the sake of a look or experiment.

Just my 2C.

Steve.

[Gwagensteve]

I'd leave it alone and do it if it needs it. There's no service interval. If the diff is quiet and doesn't leak from the pinion leave it alone IMHO. They're too easy to stuff up to pull apart for the sake of a look or experiment.

Just my 2C.

Steve.

[Bazuka]

Steve that does sound like a good idea now I consider all of the other things that need doing. I did not realize there was no service limit on diffs, I thought all bearings had a service limit...

How much diff noise is to much? I have owned two SJ's before and both had what I called noisy diffs, they wined constantly, but nothing wrong with them. I drove them and drove them and filled their diffs up with water and mud and drove them some more... Used to change diff oil about every 6 weeks because water had got in. Would flush them with petrol if it was bad. Had thick grey paint consistency diff oil on a number of occasions. I just did new oil that's it.

So how do you know when the bearings are stuffed or you need to do a rebuild? Leaking pinion seal? What about the side bearings? If the pinion seal is leaking could it just mean the seal is stuffed or bearings too? And how much noise is normal?

[SierraDan]

I wouldnt touch it unless oil poured out the pinion seal and/or sounded like a wobble board.
Although adjusting backlash im happy to do without much complaint.

[Bazuka]

SierraDan wrote:

I wouldnt touch it unless oil poured out the pinion seal and/or sounded like a wobble board.
Although adjusting backlash im happy to do without much complaint.

If oil was pouring out the pinion seal does this mean you would get the diff rebuilt or would you try a new seal first? Surely you can just put a new seal in easy enough?

Also why would you want to adjust the backlash? What does adjusting it actually do and what would symptoms be if it was not setup right?

[31zook]

If the backlash is too tight it can whine, and the pinion seal needs the flange removed, which hold preset on the pinion. Thus to change the pinion seals you would need to pull the diff apart and make sure you haven't effected the preset/changed the contact area.

[2stroker]

Gwagensteve wrote:

I'd leave it alone and do it if it needs it. There's no service interval. If the diff is quiet and doesn't leak from the pinion leave it alone IMHO. They're too easy to stuff up to pull apart for the sake of a look or experiment.

Just my 2C.

Steve.

These are wise words, 90% of the issues people have with their Suzuki's are created by trying to fix what is not broken.

[scottiej]

As everyone else said, with diffs if its not broken dont fix it.

If you do end up changing the pinion bearings but you dont change the pinion gear itself or carrier then use the exact shims that you remove, the pinion will then be at the correct depth. The pinion depth setting tool is only really needed if building up the diff with new gears or swapping the pinion into another carrier. By all means check the contact pattern but you cant really use the trial and error method when there is a crush collar involved. Every time you want to re-shim you'll more than likely need to fit a new crush collar, this is why the pinion dummy tool is used for the initial set up.

If anyone wants to read the procedure but doesnt have a service manual then it can be found on my forum.

http://www.suzukiclubuk.co.uk/forum1/vi ... =12&t=3349

I was lucky enough to pick up a kit for a good price. I would say you could borrow it but it would be a long way to travel

[jono165]

Bazuka wrote:

If oil was pouring out the pinion seal does this mean you would get the diff rebuilt or would you try a new seal first? Surely you can just put a new seal in easy enough?

When you undo the pinion nut to remove the flange to change the seal it slackens off the pressure on the crush tube and the bearing preload goes out the window so a new crush tube or a solid spacer needs to be installed and setup for the correct pre load again. I have a weeping pinion seal, I haven't changed it because of this so its fine for now.