engine and drivetrain 67 1600-2 Diff And 1/2 Axle Repair?

[prezucha]

Hi all,

 

Starting a restoration on my car and so far have it running well and now starting a complete suspension upgrade.  I have the rear sub frame out and have a couple questions about the diff and the 1/2 axles.  The diff seemed fine when I drove the car 1 mile.  Now that it's out and doing a COMPLETE suspension rebuilt front and rear, is it wise to have it checked out professionally?  A friend said he felt "flat" spots when turning the short axles.  I felt it too.  At this time should I have seals, gaskets, and whatever else typically gets checked/replaced?  What would this cost approximately?  Seems like the time to do it.

 

Also, you can see in the photos that one half axle seems to be the original, the other a replacement.  What to do about this?  Keep them as is, repaired?  Buy new ones?  Are new ones worth the investment?  Is the old type better than new ones? 

 

I've started a blog about my restoration just to keep track of what I am doing but figured this post would be seen more often.  I've posted some cool photos showing the diff with original markings and different colored paint markings...  Does anyone know the meaning of the colors?

 

Thanks!  I have 2 weeks before all my upgrade parts arrive so I have time to have the diff refurbished if this is the way to go...  Any recommendation of good shops?  I live in the Bay area near Oakland.

 

Paul

Edited April 6, 2014 by prezucha

[TobyB]

You probably know this already, but what you have there is an early 'long neck' diff in a 4.10 ratio.

Not completely unheard of, but 99% of the rest of the 2002 world has a short neck diff.

So my inclination would be to either

1- give it a coat of black paint and put it back in

because you're planning on keeping things mostly stock, or,

2- swap the entire rear over to the later style.

because you're planning on modifying the car significantly.

 

There's no reason to do #2 unless you're planning on doing things like slotting the rear for more camber,

but if something goes wrong with the diff, you'll have a lot easier time finding a short neck

in different ratios, limited slip, etc. 

BUT there are people who still have the longnecks lying around, so you could probably

find one or 2- if you weren't in a hurry.

 

I WOULD swap the old axle for a new- style one, only because the u- joint isn't a constant- velocity

joint, and it puts (theoretically) more stress on things.  But keep the old one as a spare, if it's not a total mess.

Part of the reason I would dlo this is because I have a 5 gallon bucketful of cv's, too...

Changing a halfshaft's not much harder with the rear in the car, so don't sweat this one.

 

Hope this helps, it's kinda rambling,

 

t

[prezucha]

LOL,

Just reading another resto blog and he mentioned he had the long neck diff, with 41 marking.  I had to go look and see what I have!  I plan to keep the car as is mostly.  So the question is, do I get this refurbished with new seals, etc?  It seemed ok but since it's out...

 

TobyB, are you offering to sell one of your CV 1/2 shafts?

 

Paul

[tups]

The old halfshaft, if not too worn out, should be useable, but you'll have a hoot and a half trying to replace that torn clear plastic cover on the outside end. There's no way around it, because the thing needs oil in it, but there is a writeup on the forum somewhere, which I used to replace mine. Use lots of boiling water on the boot, and sturdy spoons (!) to get it over the T-shaped end of the shaft ... it seems totally impossible at first, but it turns out it's not!

Good luck!

 

Cris

[TobyB]

Sure, I could sell you one, but the shipping would be silly- the things are almost as common as dirt, indestructable as rocks,

and you'll be able to find one locally.

Oh, and shoot, Cris' right, that boot's torn.

 

If it was not leaking, I would not touch it.  I don't remember the procedure for the long pinion nose, but on the shorties,

it involves a new crush washer, and that's a pain.  And resealing's never 100% successful, anyhow.

 

 

t

[prezucha]

Thanks tups and TobyB!  I remember seeing that tread and it looked pretty hard to replace the boot.  I did buy one so I will give that a try.  I'll also source an axle locally...

 

Cheers!

 

Paul

[ray_]

Take the CV apart and press out the pin and the boot slides right on.

 

1600s came with longneck 4.10 -- no reason to doubt that is what you got. And they are almost indestructable.

 

http://www.bmw2002faq.com/_/technical-articles/engine-and-drivetrain/bmw-2002-differentials-guide-r36

 

Have fun,

[prezucha]

Just used the instructions I found here on the forum to pass the boot over the end pin and in less than 1 hour it was done!  I was very hesitant to try this but after a beer, dinner and a glass of wine, I was ready.  Old clamps came off in 2 minutes.  Cut the old rotten boot off.  I carefully removed one of the end "caps" and saw all the needle bearings.  Didn't have the grease handy and sure enough, 3 or 4 tipped over.  Tried to get them back in but it was useless.  I dumped them out and thought, "where am I going to buy another axle?".  I then slid the round part over the end pin and carefully just inserted the 29 pins.  Put the end cap in and it was all good. 

 

 

I boiled the boot and tried putting it on over the "pin end with ball and needles".  Either this is wrong or the boot wasn't hot/pliable enough.  I didn't think this was going to work.  I carefully removed both caps and pins and laid them on their backs, all pins standing vertical.   I replaced the bent spoon in the drawer and grabbed the metal meat fork which had a thicker handle.  Heated the boot some more and in less than 30 seconds I had it on.  I simply reached through the boot with concave part of handle down on top of the far pin and just pried the boot up and over.  Yes, I thought I was about to waste $30 but it went over. 

 

 

The test will be filling it and letting it sit.  I do have a question/problem.  The clamp on the small end of the boot, when tightened all the way, still allows the clamp to spin fairly easily.  I removed the screw and bent the end to 90 degrees hoping this would help.  It tightened a bit more but still the clamp can be spun easily.  Any advice?  Can any hose clamp be used instead?  I like the old original one! 

 

See photo... 

 

At "A" I bent that little bend to more vertical than it was.  At "B", you can see the bolt is fully tightened against the clamp and cannot go further.  This is an old style clamp...

 

 

Thanks! 

Edited April 7, 2014 by prezucha

[NickVyse]

Just replace that weird old clamp with a jubilee clip. Done about 50,000kms in my 1600-2 since refreshing the stock back-end with no worries - i think one boot weeped a little oil once, but another couple of turns on the clamp and a top-up and she's been fine.

 

If you're ever tempted to swap it all for the later short nose diff don't forget you have the added headache of replacing the prop and welding in a different centre support. 

[prezucha]

Thanks NickVyse!  I'll replace the old with a new jubilee clamp!  Didn't know they were called that...

 

And replacing the diff sounds like too much trouble... It seems fine...

[prezucha]

Hi all,
Been awhile but finally the rear end is going back in!  I started installing the axle and noticed it is not symmetric.  There is an indentation on the shaft.  Does it matter is this is towards the diff or to the outside?  I have a photo of it being towards the outside before but as I randomly placed it back in, the indentation is towards the diff.  No big deal changing now if need be. Only 4 bolts in...See photo...

Thanks!

Paul

 

Oh, my other axle is the early kind with oil in the boot.  Please tell me what kind of fluid goes in there.  I have Redline tranny fluid and the 75W90 gear oil.  Is the gear oil correct or do I go to O'Reilly's and get something else?

Edited July 15, 2014 by prezucha

[Hans]

75W90 is good. There is a quantity listed in the shop manual or perhaps back of owner's manual. Use a funnel. Boot should be a little over half full when lying flat as a rough indicator. I've used a metal shoe horn to get the boot over the T.

 

 

 

I'm looking for some of those asymmetrical CV joints if anyone has some.

[Hans]

May be a bit late now, but there is/was a very thin O ring in the big metal cap that fits between the boot and the the main housing. I've rescued a few, got a local bearing shop to make a few, either way I use some silicone in there.

May be a bit late now, but there is/was a very thin O ring in the big metal cap that fits between the boot and the the main housing. I've rescued a few, got a local bearing shop to make a few, either way I use some silicone in there after cleaning out rust, etc..

[prezucha]

Hi Hans, thanks for reminding me about the o-ring.  I had Blunt order me one but haven't installed it yet.  I will do so today!  You used silicone on the o-ring as an extra sealer?

 

Do you know about the other newer style axle?  Can it go in either way?

 

Thanks!

 

Paul

[Hans]

Depends on how pitted the two surfaces are. I clean up with rotary wire brush. It's a little insurance. I've had seeping out the small end when the bellows wasn't sitting flush with shoulder.

Not sure which way CV joint shaft goes.