Rear hub carrier/wishbone question

More thinking! good for my grey matter!!!

the suspension is in te form of two paralelograms One on each side. Each parallelogram is hinged at the cornmers. whn the suspension is jounced r bouced, each joint mujst move. If thje oputbpsrd corners on each side are bounmd, the l;ower part of the whelss must move to the outside. reverse camber. surely not intended. teh idea of fur hinges is to amintain camber trugh bpounce and jonce.

odd that bot are locked??

Hi Stephen. …you really dont want to be jacking up under the ali hub carrier…you could damage it…when correctly assembled the bearing is only fractionaly wider than the carrier…(a few thou of an inch)…the easy test is with the wheels sitting in the ground bounce the car…if it bounces then the carrier must be pivoting…also as i said you will see wear if the ali is on/rubbing the wishbone…Steve

Carl, Steve: Thanks again. I will check and get back to you

Just one last question: If it bounces, wouldn’t that mean that I should be able to get a feeler gauge between the carrier and wishbone?

Not necessarily. It could be at “zero” clearance where it is wearing on the hub carrier, but can still pivot. I would be pretty surprised if it does not pivot even if it is too tight. The wishbone has quite a lot of mechanical advantage on the pivot point.

So I walked by the car last night: It bounces - you all were right - however, the wishbone is wearing/scraping on the hub carrier (both sides) . I will take out one carrier and investigate further.
Thanks for all your support.

The outer races are pressed to the hub and the distance between the two ends is fixed.
The inner races should extend beyond the hub by a fraction of a mm, even with zero end-float.

If the aluminium is scraping on the wishbone there is something seriously amis.
Only way to find out is to remove the hub and inspect the bearings. Best get some new ones.

A good idea is also to change the felt seals with double lip seals.

If you decide to use a jack to open the wishbone clearance be extremely careful. It has to be tight and if you over do it you will not be able to bend it back.

I would not recommend the use of washers between the hub and the wishbone. They are soft and they will deform. It might also affect the geometry if you put only in one side.

It’s not a complex setup, just fiddly. The ROM is clear on how it all goes together. It’s been a couple of years since I did mine. The bearings are located in the hub carrier by sleeve 15. You use shims 14 so that bearing 16 and it’s twin on the other end (not shown) cannot be pressed “too deep” into the hub carrier. I suspect these shims were omitted, or not enough used, which means the bearings are too deep in the carrier, which means the wishbone can be pinched down by shaft 23 and nut 26, with the bearing too deep to stop it, it is pinching in enough to interfere. Hopefully when you take it apart it will spring back to it’s correct dimension. No point in describing the whole setup procedure here, refer to the ROM. But this is the basic idea. @Aristides please correct me if I am way off here.

Aristides, Bob: Thanks for the valuable input! I will disassemble the hub carrier over the next few weeks (as time permits) and will report back.

The bearings ( no 16) are tapered roller bearings like front wheel bearings and the tube 15 sits between the inner races of the two bearings, one either side of the hub. The purpose of the shims (14) is to set the endfloat of those bearings so they can rotate easily, but with not too much so that the rollers don’t run correctly on their cages ( tilt slighty, causing uneven loading and digging into the race) If the endfloat is too small, when tightened up, the bearings will not rotate and your suspension is seized, or at least, very stiff, and the bearings will wear prematurely. I, personally, have never seen the shims on the outside of the bearings, but they are actually shown in both the service and parts manuals, but only as required. You can set the endfloat with the hub removed from the car; this is much easier than wrestling with it on the car.

2 Likes

There are shims between the bearings to set preload, and shims outside of the bearings to center the carrier in the yoke and to take up clearance; different part numbers.

Correct. My parts book lists them as C16626- to C16626\3. I assumed they were the same apart from thickness, seems not. I stand corrected.

Hi Kevin…the bearings are not set up with endfloat…they must be set with pre load…however once set the hub will not be a tight fit in the wishbone so shims must be used between the outside of the hub bearing and the wishbone. …these shims do 3 things…they centralise the hub in the wishbone. …they prevent any sideways movement of the hub in the wishbone and they prevent any chance if the wishbone bending in as you tighten…these details are in the service manual where there is a very detailed set uo procedure. …Steve

1 Like

Yes correct, end-float would absolutely shorten the life of the bearings.
Regardless what the manual says, front wheels for example, I mount all tapered bearings with pre-load.

Tha manual says pre load for the hub carrier

Perhaps I misunderstand the terminology, but when setting front wheel bearings, would you not tighten the nut until the wheel starts to bind, at which point it has some degree of preload, and then back it off until it spins freely, at which point it will have some degree of endfloat?


Hi Kevin…there is some missunderstanding here…first lets talk about the jag specification in the jag service manual…yes jaguar specified front wheel bearing endfloat…Aristidas is refering to bearing manufacturers and others opinions that taper roller bearings should always be set up with preload and some decide to set their wheel bearings like that(this is a bad idea on Jag front wheel bearings unless you fit a bearing spacer to “lock” the bearings or the bearing will just wear the stub axel)…now lets talk about the rear hub…you really have to read the full set up procedure in the service manual…your photo shows measureing the end float with feeler guage when the hub is in a set up rig on the bench…you then use this measurement to calculate and shim the bearings correctly to give you preload…now the problem is getting the hub carrier into the wishbone and keeping this preload …thats when you use shims to take up free play betwee the set up hub and wishbone…Steve

Indeed Steve, and to prevent this I used Loktite betwween the bearing and the stub axle.
Never the less, it’s certain that with end-float the bearing will definitely spin and wear the stub axle, as many have witnesed.

1 Like

Sure is alot of thinkig going on here

It seems to me that the whole idea is to set the tapered bearing just right in the tapered seat Front hub has two that need to be seted just right. the technique s to tighten the nut til the berarigs, fron and basack ar seted n the seat!! Now, that is too tight nd the bearin rollers cn ot spin freely. So, back off . that creates a tad of float.

i have done that many a time on various critters. commencng with mY T ford, circa 46. And more at my after class job in my college yers.

But, unti now, never any issue with binding the iner race of the inner bearing to the axle!!!

Only once did I have a front wheel bearing fail. MY t. The hub broke!! Pulled me into a low rock fence. But freed up and I limped home. had to deal ith the wner of the busted fence. Dad elped out there. A guy from work fixed it for a small sum.

Another way . Crush sleeves to establish foat. I recall an old mechanic shoing us how on m y 34 chevrolet. He used a chunk of radator hose!!!

Crl

1 Like

Over the weekend, I disassembled the hub carrier and replaced the bearings, this time with the correct spacing. Thanks to all your advice it was a quite straightforward job. Thanks again!

2 Likes