Diff Carrier bearing pre-load?

[TA22 GT]

Hi,
I'm currently fitting a new TRD LSD in my TA22 GT. The pinion is already set and I'm fitting the same crown ring to the new centre with new bearings.
After I set the right backlash (2 to 5 thou?) etc, I'm wondering how much load I should apply to the carrier bearings?

I've read that it should be tight, eg 50lbs/ft type of thing, however for tapered bearings I've always set these with almost finger tight load to ensure they don't bind up when they heat up.

SO, how much pre load should the diff carrier bearings have? The adjustment is via the screwed adjusting caps....

Thanks,
Simon

[wilbo666]

As far as I am aware the method to set up preload is as follows...

Set the pinion preload, and then set the backlash / pinion height; i.e. get the correct wiping pattern, then set the total preload.


see link for how to set up an IRS F series diff...
http://www.cygnusx1.net/supra/librar...ra/RA_029.html

And to go even furthur SKF? have a document regarding tapered wheel bearings and preload vs life that is an interesting read I may try to find it again for you later...

Cheers
Wilbo

[o_man_ra23]

I normally get a VERY blunt cold chisel, and give the carrier adjuster a few reasonable taps (not big swings, and not baby touches) with a 20-30Oz ball pien hammer, and then re-check lash. It really does become quite a play, as you cant turn the preload adjusters with the caps tightened fully, and they move slightly when you nip them up. Of course, if you had an attachment to go from the adjuster to a torque wrench, then this would be preferred to a hammer and cold chisel, but not too many people have the special tool required. Perhaps checking the Haynes manual may be a good starting point??

Cheers, Owen

[TA22 GT]

Wilbo,
Thats a good article. I'm fine setting the backlash, pinion etc, just still can't decide how much load to put on the carrier bearings.
MAybe I'll just nip it up, something like 15lb/ft. This is tighter than I would normally set tapered wheel bearings. Too loose is not gonna be good for ring wear and too tight might cause premature bearing failure.....Its needs to be right given the load that going through the rear end....

Cheers,
Simon

[river]

Hi,

Is this a 6.7inch LSD?

If so, drive pinion bearing pre-load, rotating (with new bearings) is 2.4 - 4.4kg (5.3 - 9.7 lb).

Hope this helps. If you want more info then let me know as I have the manual for pulling down and rebuilding/checking the TA22 6.7inch (and 6.38inch) diffs, including the LSD.

seeyuzz
river

[TA22 GT]

River,
The pinion is set, do you have a pre load figure for the carrier bearings and amount of backlash?
Yes, this is for a T series TRD LSD.

Cheers,
Simon

[river]

Hi,

Here's some info....

Differential case side bearing preload => Tighten both nuts until ring gear has no play, and then tighten the nut on one side aditionally by 1 - 1.5 notches.

Drive Pinion to ring gear backlash => 0.13 - 0.18mm

Side gear backlash => 0.05 - 0.20mm

Ring gear run-out limit => 0.05mm

Diff case run-out limit => 0.05mm

Drive Pinion spacer length (specified) => 56.5mm (for 6.7inch diff)
Drive Pinion spacer length (limit) => 54.0mm (for 6.7inch diff)

Side gear thrust washer No.5 thickness => 2.485 - 2.515mm

Clutch member thrust washer clearance => 1.965 - 2.035mm

Clutch plate thickness => 1.985 - 2.015mm

Side gear thrust clearance => 0.05 - 0.15mm

There are some other measurements but these depend upon the differential case code letter (A, B, C, D, E or F) - not to be confused with diff type such as as F, T, etc. You need to measure the assembled distance of the clutch plates (in mm). Depending upon the case code and the distance, you need to select the appropriate thrust washers.

If you can measure that & tell me the case code then I can give you the thrust washer thickness codes.

If all the above confuses you then I can scan the diff section and email to you, but I won't be able to get all this done today - and the size will be quite a few meg.

seeyuzz
river

[TA22 GT]

River,
The TRD LSD I have is already assembled. Whats the deal with the thrust washers? I assume these are inside the centre itself?
I'm guessing I don't have to worry about thrust washers?

Cheers,
Simon