Dif rebuild questions

[jon1d]

Tinkas figures sound right . I tested mine at 25lbs .
You remove the amount of clutch plates from 5 to 3. If you do not derate the rear will only under high loads transfer and not progressive at a lower load so it will almost feel like a locked diff.

[sunday]

Tinkas figures sound right . I tested mine at 25lbs .
You remove the amount of clutch plates from 5 to 3. If you do not derate the rear will only under high loads transfer and not progressive at a lower load so it will almost feel like a locked diff.

Thanks for this info. I've tested with dynamometer and mine is locked at least until 100lbs so for sure not derated (this can explain "strange" behaviour on corners at low speed of the car before i dismantled it).

[Happy Jim]

Don’t remove the plates, just re-order them to have less friction to drive plates. For example plate A is friction, plate B is drive, currently you will have ABABA, ABABA which gives you a total of 8 friction to drive faces, if you re-order to AAABB, AAABB then you only have 2 friction to drive faces and therefore you reduce the torque required to break the lock (ie, de-rate).
You will need to experiment for the right number of faces to achieve the 25-35lb ft though.

Regards

Jim

[TINKA]

I did exactly as Jim says, just put the plates in a different order exactly as he lists all the friction plates together and all the drive plates together. Worked a treat for me.

[jon1d]

I think it does depend on your diff and the LSD clutch plates and friction surfaces. The build manual I had changed the quality but you should obtain a manual. I had one for the Dana 44 Spicer diff . The Salisbury diff manuals are more difficult to find. The is a very good youtube video on a diff overhaul. I will post the link.

[justinb]

Try the attached link.

https://manualzz.com/doc/6355718/mas...service-manual

Its a good place to start and covers aspects of the 4HA / 4HU diff. Gives backlash and preload setting and torque settings plus indication of gear pattern.

I've got a 4HU service doc that I got when I used to work for Jag many years ago. I think its also available on the internet somewhere but I'll see if I can find it.

Its similar to Dana 44 but not entirely so some build advice is the same and some, but not by any means all parts can be interchanged, mostly in the powerloc carrier. If you strip it down you can find matching bearings by the part numbers or by taking accurate measurements of bore and outer race size.

As others have said, the friction discs can be reordered to reduce the "loc" plus there are some other discs you can get new which have less friction to them. I'll try and find the part number.


This guy is good and worth watching.....https://www.youtube.com/watch?v=OurJHaiy6kI

[mark chambers]

Which DAX are you building what gearbox and engine do you have?

[sunday]

I've done some "homework" and plan to rebuild dif this winter to 3.07 ratio and with derating of clutch plates.
I've ordered a Motive gear dana44 3.07 ratio crown+pinion which need some adjustements to be put in a salisbury (bolts/pinion bearings).
If some of you are familliar with dana parts, i've a question : usually pinion has a marking which indicates either offset of pinion position vs therorical position (+2 for example indicates 2"625+2=2"627), either an absolute pinion depth. In my case pinion is marked with 23 (see picture attached).
I assume it means a 2"623 absolute pos : in theory, according to motive documentation, motive gear are marked with a complete absolute pos ... so don't known if my assumption is correct ?
DanaPinion.jpg