Axle Play - How Much?

[demuire]

How much side-to-side axle play is acceptable? I've got a KE35 Corolla with an RA28 diff, running Bluebird TRX rear discs brakes. I bought the diff already set up with the brakes.

 

For as long as I can remember since I put the diff in there's always been a clunking sound from the back of the car when I go around some corners, but I've never really known what it was. I have a clutch style Cusco LSD and I know this makes clunking sounds as it engages and disengages.

 

Anyway, last event I did I noticed that at least one of my discs was occasionally scraping on my caliper when I went around some corners, it only happened when I was coasting around corners. Looked under the car, and it looks like there's oil leaking from one axle, and there's a little bit of misting from the other.

 

Took the calipers and discs off, and measured the play in the axle. Right axle is about 1 or 1.5mm, no sounds, left axle is about 3.5mm, with a clunk as it goes from one extreme to the other. How much is acceptable? I had a look at a spare axle I have and noticed that there is some side-to-side movement in the bearing (which is new), so I guess some play is normal. But how much?

 

At the moment I'm thinking the right axle is fine, left axle needs to be addressed... Maybe I need a spacer between the bearing and the disc brake backing plate? The left one has been replaced before (a few months after I originally got the diff in), maybe it's not quite the same as the right one?

 

Any ideas?

 

*edit* have since discovered that I think I have an RA23 diff, not an RA28. Only differences as far as I can tell are different axle lengths.

Edited July 2, 2006 by demuire

[Raven]

I'm not sure about the spacing but here are a few things to check out....

 

Has the diff been shortened at all?

 

If it has, maybe the axle has been shortened too much? Have you compared the diff to another one to see if it has the same amount of play?

[demuire]

Diff hasn't been shortened as far as I can tell. Don't have another diff to compare to, it's really hard to find RA28 diffs!

[Raven]

RA28 would be the same as a TA22/RA23 wouldnt it?

 

Pity you didnt post this before midday my time too. I was down at a self-serve wrecker and there were 3 RA28's sitting there with diffs in them.

Edited July 1, 2006 by Raven

[Redwarf]

A couple of mil I'd be fine with. 4 is maybe getting excessive. I don't think I'd be happy with the left one...

[Teddy]

ive been lookin through every book i have fook, and i can't find any axial run out specs.

 

New bearings will have some movement, but its really minimal. 3.5 sounds like its tooo much tho...

[demuire]

Thought so, thanks for the replies. Will take the left axle apart and see if I can see anything unusual, else I will assume that it is a mismatched bearing/axle/disc brake backing plate or something like that.

 

Raven: No, RA28 seems to have different axles to TA22 I think RA23. RA23 and RA28 have same bearings I think, but different length axles if I'm not mistaken. TA22 has smaller bearings. Found this out when I bent my left axle and had to go around looking for a spare axle (which I have done, but now has too much play...)

 

Another question: Once a bearing has been put onto an axle, can it be removed and put onto another axle? Or would that destroy the bearing? I had a brand new bearing on my old left axle (which is now bent), would be a shame to have to buy a new bearing to fix this 2nd axle...

Edited July 2, 2006 by demuire

[demuire]

OK, both axles are out. The bearings are 17mm thick. They appear to be fine, compared them with a brand new bearing I have, and they have the same amount of side-to-side play in them (about 1mm, maybe a little less, hard to tell) and they all roll without any gritty feelings or sounds about them.

 

At first I took the left one out, and then measured the distance between the diff end of the bearing space and the outside edge of the disc brake backing plate, and that was 20mm and I thought "a-ha!". But then I took the right axle out, and it was the same. Measured the axles, they seem to be the same length. Measured the position of the bearings on the axles, they're the same. Hmm.

 

I'll take some photos.

 

Maybe I'll swap the axles around and see if the problems swap sides too?

[demuire]

Well, swapped the axles around and same problem with same sides. Did notice that the right bearing is pretty tight in the diff housing, so maybe that's why it doesn't appear to have any play, where's the left one isn't really very tight (it's not loose either).

 

I'm thinking that I need to get a 3mm spacer made to go inside the diff before the bearing goes in, so that the bearing is properly sandwiched between the retainer plate and the inside of the diff?

 

The only problem I can see with this is that there's 3mm less bearing being supported by the diff housing itself. Is this a problem? There's still a fair bit of bearing being supported by the diff...

 

Here pictures:

 

 

[demuire]

After some discussion with people on PF and on BMSC, we've come to the conclusion that I either need a 3mm spacer on the inside or outside of the bearing, or a 20mm bearing that will fit on the axle.

 

Have called bearing shop, waiting for a return phone call to tell me that they've found a bearing that will fit... Else will call the machine shop to get some 3mm spacers made up.

[demuire]

No such bearing exists (closest is 22mm wide I think, which is too wide). So getting 2 spacers made up for a total cost of $35. Hopefully it works.

[demuire]

Note to self. The inside diameter of a ring, is the outside diameter minus (2 x thickness of the ring).

 

What does this mean? If you want a ring that is 72mm OD, and 3mm thick, then the ID is 66mm, NOT 69mm. Dammit.

 

Oh well, it's only money. Money I don't have :dance:

[demuire]

After speaking to mechanic, I cut the spacers with a hacksaw and spread them to get on the wheel side of the bearing. It sounded like a good idea at the time and I'm sure they still work just as effectively, but I must say, it's made putting the axles in a hello of a lot harder because they aren't quite round anymore (I couldn't seem to bend them back to exactly the same shape as they started out). Trying to get them to line up and slot into the hole was really really hard and time consuming! I hope I never ever have to take the axles out again!

 

Right axle now appears to have zero play (hmm, is this worrying? Considering the bearing itself has a tiny bit of play), but seems to spin freely, left axle has maybe about 0.5 or 1mm (didn't get a chance to measure properly). Calipers are back on, need to fill the diff back up with oil, put wheels on and see if it all works!

[Biggo]

Love the back yard machanicie work. Seems like thats how id do mine when trialing it.

 

I say, give it a shot for a bit, then pull it apart again and see if you can fix it better or if it needs fixing. Sort of like goin over your dodgies :dance: (i still am!!!)