Replacement of TR7 Rear Wheel Bearings

[saabfast]

In the MOT last weekend the tester noted that the rear wheel bearings had some play and a slight rumble. The car is an '81 with 5 speed box and passed with an advisory. I have just read the great writeup by Shauniedawn which gives a good idea of the problems of changing them and raises a few queries (for me):
1. I want to do it with the axle in place, will the oil pour out when the halfshafts are removed? Haven't had a chance to look at the comparative level of the filler plug yet.
2. The writeup notes that the new bearing etc could be slid on just by heating and did not need a press. Could they be removed the same way, or would the heat dissipate in the shaft too fast? (My equipment does not extend to a 12T press). Anyone tried this?

I knew there was a bit of play, has been for a few years, but now its been 'officially' noted I'm a bit concerned about 125 miles each way to Billing. I will not have time to do it before then.

[REPLIC8]

Hi Alan,
How much play have they got? All TR7 rear bearings have some play, a mm or so is not unusual. If they're not making a rumbling noise when driving I would leave well alone and not worry about it. Most after market bearings available now are crap anyway so unless you can find so NOS ones I wouldn't bother.

[saabfast]

Hi Andy,
I had not noticed any rumbling, but then I only drive with the roof down and most things short of Concorde are drowned out by the exhaust. The amount of movement is not too bad but he did show me it with a lever under the wheel and a slight clonk that sounded, also slight rumble when he span the wheels. He said it was not too bad yet, just be aware of it and watch it does not seize.

I have only found one NOS bearing available on ebay as yet, others are after market and it is the sort of job where I am wary of them.

[john 215]

Hi Alan,

As Andy correctly says as a taper bearing will have a slight amount play in it.

As far as removal refit, should be very little if any oil come out, there is an oil seal in the casing between the diff and bearing ( bearing is lubricated by its grease ) and always used a press for removal and fit, the collar that holds the bearing can be ' stiff ' to remove.

Cheers John

[saabfast]

Thanks John, always wondered why they used a taper bearing on the rear when you can't 'adjust' it like the front.

Re the oil, I was trying to avoid taking the brake shoes off as they always seem a pain to get back and working nicely. I don't think the manual mentions removing them but I might have missed a reference to another page! The outer seal comes out with the shaft but here is the inner seal? Its not really clear in the manual except that it is replaced by removing the half shaft.
Might have to pull the half shafts and take them to a garage to press off if they won't move with a bit of heat.

[john 215]

Hi Alan,

Its only the 5 speed has taper bearings, 4 speed has ball bearings.

You can leave the brake backplate where it is and pull the shaft out through the centre.

The inner seal sits inside the axle casing, if you look its part number is GHS 186 -

Triumph TR7 Rear Axle Casing and Halfshafts.JPG (54.79 KiB) Viewed 8146 times

Cheers John

[REPLIC8]

Alan,
Before you go down the replacement road, why don't you run it up to Billing and let someone take a look at it for you. They may be fine, and it's a lot of work if it's unnecessary. I've had several MOT testers give advisories on perfectly good bearings.

[saabfast]

Yes, often had some discussion on the front ones and had to teach one young tester what taper bearings were, he had not come across them before but at least had heard of them.

I am planning coming to Billing, all things being equal, but have to admit I could hear a rumble when he span the wheel and showed me what he was talking about. Getting new respect for Halfords as they were very helpful at the MOT, may have been something to do with the tester having a TR6 and saying my car was a lot more solid than his!

[REPLIC8]

Again, all my TR's have made a bit of a grumbly noise if you spin a rear wheel with the back end jacked up. I think it comes from the diff when the planetary gears are spinning as it slips coz only one wheel is turning.
Normally if a bearing is knackered you would here it during cornering one way or the other.

[saabfast]

Well, finally got around to starting the bearing change. Pulled the half shafts yesterday between showers and wind. It was quite tough, my slide hammer claw was too large so had to use the puller arms which kept falling out of the holes and sending me flying. Finally got them to stay apart with some stiff foam between the arms but not easy on your own. Also took quite a lot of force to get them out. Note that if your drive has a bit of a crossfall like mine the oil DOES come out of he lower side axle tube!
I have been trying the search for a very good writeup which done on here a few years ago without luck. The outer race of the bearings has stayed in the axle tube - is there a recommended way to get them out? I have not really tried yet but they appear quite tight and you cannot get behind them. I hope the inner oil seal can just be pulled out with a pick.
The right side half shaft is quite a bit longer than the left (will measure and post lengths later with pic if I can) so I need to get a cheapish press to take the length (and replace the rear suspension bushes). Has anyone ever tried the Fox Hunter 12T hydraulic presses on ebay?

[Beans]

... The outer race of the bearings has stayed in the axle tube - is there a recommended way to get them out? ...

Rather straight forward;
• Remove the brake drums;
• Undo the 4 nuts/bolts that hold the half shaft in place;
• Leave two bolts in place to keep the back plate in the correct location;
• Re-fit drums the wrong way round and tap them with a rubber mallet until the shaft comes out;
• Use a slide hammer to remove the outer bearing races from the back axle (see below);
• Remove seals with a hooked tool;
• Weaken the collars with an axle grinder and use a cold chisel to remove them (make sure not to damage the half shafts);
• Use hydraulic press to fit new bearings and collars.

[saabfast]

Photo of the half shafts:

Triumph TR7 halfshafts.JPG (70.03 KiB) Viewed 8147 times

Axle Halfshafts.JPG (34.82 KiB) Viewed 8147 times

The lengths from the back of the wheelstud plate are:
Right: 725mm
Left: 665mm

The distance from the back of the plate to the top of the bearing retaining rings is 100mm.

One thing I have noticed is that the retaining rings in the new kit are about 3mm narrower than the existing ones so there will be a gap to the circlips which are currently hard against the retaining rings. Is there a recommended way of getting the circlips off or is it just a case of levering with a screwdriver?

[saabfast]

Thanks Beans.
I have the shafts out, its just the outer races of the bearings which I need to remove from the tube and I could not see enough ridge to get a hook onto. It was too cold to spend to much longer out there so will have another go next weekend.

[REPLIC8]

Alan,
If you don't want to buy a press that you'll probably never use again, I would recommend taking them to a decent classic workshop and paying a few quid for them to it for you. I had mine done on the TR8 down at Faversham Classics. They normally only work on Triumph Stags, but were more than happy to help out with this job.

[saabfast]

I was thinking of that Andy but I have the bushes to do and my son has several cars which need bushes pressed in so it will get used (even if not so much by me!). He has just broken his vice pressing something. The press does not cost a lot more than getting a garage to press the bearings on and will be there when needed. My biggest problem is clearing space in the garage for it, otherwise I can see it migrating down to Ashford.