Diff rebuilding

[wimpus]

Hi, 

I had a 4.11 diff of an mk3 spit fully in pieces in my stock.

Had a go to set it up and got good results.

So now the 3.63 diff that was once in Fox (spit 1500).

 

It made noise etc, got it open this evening. fibre shims are gone on the sunwheels.. 😔

Also pinion and crown wheel has a bit to much play.

 

Seems only mkiv/1500 use fibre ones, mk3 copper/bronze.

 

Now can the early shims fit the 1500 diff ?

Dont really thrust those fibre ones.

 

Also bearings, does anyone know all the numbers? A friend of mine could already look at his work if the supplier can get them.

 

Already thanks 

 

[Peter Truman]

On my Vitesse 3.89 Diff the planet gears brass thrust washers (clearly stamped 37) had torn in half and been spat out, when I rebuilt it I used the slightly dished GM Holden ones of the same thickness appears OK no noise's, i assume there still in place prior to strip down there wasn't any noise either and the roto flex donut took any bangs and slack up!

[wimpus]

More stuff broken.. 

Or cracked !

 

 

Hopefully can use the early style thrust washers /shim as the suppliers only sell the mk3 to early 1500 shim in just the size I need.

[wimpus]

Now fully apart.. time to search for bearings

[Clive]

1 hour ago, wimpus said:

Now fully apart.. time to search for bearings

Do all the bearings need replacing? Many of the better gearbox/diff builders only replace those that need to be replaced. A good clean, squirt of WD40 and then an airline to spin the bearings up should tell you if they are OK. 

My T9 gearbox has had a heck of a life, I replaced the input shaft and mainshaft tip bearings, but that was down to play. When I had BGH (probably the best T9 builder out there) they checked all teh other bearings, and declared them good to be reused. They did replace 5th gear, the case hardening was almost through. They reckon it could have done at least 150000 hard miles in the original car, a V6 4wd sierra. They also fitted a better set of synchros, but they avoid new ones at all costs.

[wimpus]

10 hours ago, clive said:

Do all the bearings need replacing? Many of the better gearbox/diff builders only replace those that need to be replaced. A good clean, squirt of WD40 and then an airline to spin the bearings up should tell you if they are OK. 

My T9 gearbox has had a heck of a life, I replaced the input shaft and mainshaft tip bearings, but that was down to play. When I had BGH (probably the best T9 builder out there) they checked all teh other bearings, and declared them good to be reused. They did replace 5th gear, the case hardening was almost through. They reckon it could have done at least 150000 hard miles in the original car, a V6 4wd sierra. They also fitted a better set of synchros, but they avoid new ones at all costs.

Clive, I will have a look.

Sadly 2 bearings are broken (my fault).

 

With gearbox's i know the new syncro's can be worse then the old , talking about spitfire's.

But will have a look

[wimpus]

All new bearings where ordered locally, but one not in stock.

So waiting for that to arrive.

Got all the spacers and thrustwashers and started to put back together a few pieces. 

 

[Pete Lewis]

if you are fitting new bearings how will you manage/calculate the mounting distance of the pinions new  position ???

Pete

 

[wimpus]

1 hour ago, Pete Lewis said:

if you are fitting new bearings how will you manage/calculate the mounting distance of the pinions new  position ???

Pete

 

Ive watched video's and used a diff that was given to me in parts to test on how to do it.

 

Dail gauge and feeler gauges do the trick.

 

 

https://youtu.be/FCvjDfJwW0w

 

[Pete Lewis]

that will be ok to set the tooth backlash but doesnt address the mounting distance of the projected  cone of the pinion to the centreline of the crownhwheel 

if the bearings are still on the pinion measure from the bearing to the tip of the pinion make sure  with any new bearing it is EXACTLY the same 

    mounting distance is controlled by shim adjustment between the pinion inner bearing and the back of the pinion 

get it wrong by a few thou  "  and you have a howler 

pictures are  just for illustrations 

  the best running error is etched on the end of the pinion as + or -  the thou" from the theoretical geometry

Pete

 

[wimpus]

Got the new bearings from my local supplier.

Sadly once home I spotted a mistake for the carrier bearings.

This evening going after the right items.

 

Did install what I could yesterday evening.

Freezer does wonders when fitting bearings 😄

 

Also ordered another spacer and shims.

So I can get rid of the collapsible spacer.

[wimpus]

The mistake of the supplier was sorted.

Froze the pinion shaft in.

Found a piece of old gas pipe that fitted great to press the bearings on.

 

Carrier bearings installed.

More parts arrive today, so this weekend diff fun.