Fitting a billet side cover... Help!

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UKLuke72
Posts: 177
Joined: Fri Nov 25, 2011 8:28 pm

Fitting a billet side cover... Help!

Post by UKLuke72 » Wed Feb 05, 2020 11:09 am

So i kinda thought I could bolt a HD side cover onto my swing axle trans and help it out a little.

I've since realised I'd need a way of checking both the diff bearing pre-load and the ring and pinion back lash... Neither of which I am equipped to do as per the Bentley manual.

Have you guys got any ingenious tricks you could impart to potentially make this possible?

Street car, stock trans. I thoughts I'd add a sideplate seeing as it's getting a 2276 bolted to it but it seems it's not that simple.

Bruce2
Posts: 6926
Joined: Sat Oct 13, 2001 3:01 am

Re: Fitting a billet side cover... Help!

Post by Bruce2 » Thu Feb 06, 2020 3:32 am

Street car with radial tires, use the stock side cover.

Casting Timmy
Posts: 145
Joined: Sun Nov 17, 2013 9:42 pm

Re: Fitting a billet side cover... Help!

Post by Casting Timmy » Thu Feb 06, 2020 7:43 am

Some determine preload with seeing how much the side cover pops off when unbolting it, I experimented with that and it didn't work well for me.

An old set of bearings can be sanded down on the OD to a slip fit into the side covers. You can then under shim it and measure side to side play to get the next try super close or a few methods with those. If you have access and abilities for it you can sand the ID as well to make it even faster to try different shims. In the end, just use a constructive method to approach it and compare the "set up" bearings to the final bearings for thickness for your last check.

You should be able to measure what you have and be super close for just adding a side cover. You can probably add a touch to the stock side cover side and turn and feel to see if the bearings have preload or not.

Backlash the simplest method I can think of off the top of my head, but haven't tried it, would be putting a mag base on the end of the diff and having it touch something at the edge of the ring gear diameter outside the case. You could do some math and mount a piece of angle iron outside the case and mark where the dial indicator should touch it. Technically you could also have the dial indicator touch something else a farther distance away as long as you premeasure the current backlash and post backlash to the same it will be the same. (If you're 2x farther away the backlash would be double, assuming you want to compare to factory specs or others specs.)

Probably a lot of other ways to skin the cat so to speak depending on what you have.

Kafer_Mike
Posts: 412
Joined: Fri Oct 04, 2002 3:01 am

Re: Fitting a billet side cover... Help!

Post by Kafer_Mike » Thu Feb 06, 2020 9:34 am

Bruce2 wrote:
Thu Feb 06, 2020 3:32 am
Street car with radial tires, use the stock side cover.
Agree with Bruce. If you're still worried about side cover flex and deflection, you can use this without having to mess with pre-load/backlash.
Image

Bruce.m
Posts: 179
Joined: Sun Aug 11, 2013 3:44 pm

Re: Fitting a billet side cover... Help!

Post by Bruce.m » Thu Feb 06, 2020 12:27 pm

If the pre-load & backlash is assumed to be currently in spec. The shims need to place the bearing in the same location as currently?

So, could you not just compare the stock cover to HD cover and modify the shim choice to remove any difference. Perhaps set up a dial indicator & stand to read zero on the stock cover (comparing the case mating surface to the bearing surface) then switch over to the HD cover & measure the difference from the zero reading.

Just a suggestion.... not from experience.

Bruce2
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Joined: Sat Oct 13, 2001 3:01 am

Re: Fitting a billet side cover... Help!

Post by Bruce2 » Thu Feb 06, 2020 6:08 pm

Stock side cover:

Image

Dougy Dee
Posts: 158
Joined: Tue Oct 09, 2001 3:01 am

Re: Fitting a billet side cover... Help!

Post by Dougy Dee » Sat Feb 08, 2020 9:24 am

When I was started doing trans I modified a stock diff so that it just slid between the diff bearings.
I was able to measure the distance between side covers and calculate shims required.
I then added the HD side cover in and remeasured. The difference I then added/subtracted to the ring gear side.
Several I had needed .020 added to the shim pack!
Problem is in assuming the bearing recess is parallel to the mounting surface...Chucking in a lathe and truing them up is often necessary.

UKLuke72
Posts: 177
Joined: Fri Nov 25, 2011 8:28 pm

Re: Fitting a billet side cover... Help!

Post by UKLuke72 » Fri Feb 14, 2020 10:49 am

Thank you for all of your input guys.
Invaluable as ever. Also saved me £80 :D

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