Differential output shaft bolts fouling

E-Type
1

Hi, long time reader, first time poster…

I just got my 1970 S2 power lock differential rebuilt and was about to pop it back in the IRS to start putting it all back together and i noticed that the bolts on the output shaft flange knock against the bolts on the differential. There is a fair amount of float and the flanges can be pulled outwards which stops this.

The shop that rebuilt the diff started to tell me that this would be sorted on installation before we got cut off… but i cant see how this could be overcome as the weight of the car would always push the driveshafts in and cause the bolts to hit each other in a rather catastrophic manner?

I’m speaking to the rebuild folks again tomorrow, but I’m guessing this is not good and should be sent back to be rebuilt properly?

First question i couldn’t answer from the archives… i guess I’m getting deep into this build. Thanks in advance for advice.

image

2

I hate to say this but it looks like the rebuilder was clueless. There’s no way you give something that doesn’t rotate back to the customer. If there is a washer under the bolt head, you may be able to remove that to make clearance. It might be time to find another rebuilder.

3

Hard to tell from that photo, but looks to me like the flanges may be mounted on the shafts backwards…

Regards,
Ray L.

4

If there is any in and out float on the axles, they need to be repaired. There is no adjustment on installation. Looks like there is a mix of lock washers also. The proper ones are really thin. The silver one on the right of the pictures looks a bit thick. The one up front looks proper. Earlier cars had drilled bolts and used wire tie to secure. They still used the lock washers.

5

Thanks all, that confirms my suspicions. I’ll get it sent back and see if i can get the job done properly this time. The company i used came well recommended, hopefully they can come good.

Glad i spotted it before the whole IRS was in and i moved the car.

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6

Just looking at how dirty/rusty it all is they don’t seem to have taken much care.

When our diffs come back from the shop they look brand new.

7

The equivalent of the painter’s ‘It’ll look fine when it’s dry’.

Best of luck, hopefully it can be resolved by the same shop.

PS - How mine looked when received from Dick/Coventry West (note thin washers, etc):

Bolts
Bolts900×600 99.7 KB

8

You got lucky once.
I wouldn’t go back to the same rebuilder as you may find something else wrong…after you have the IRS assembled and installed.

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9

Well I think this has turned out ok. Using the comments here I rang up the company and explained my problem, the owner was quite surprised and came over to my home in person to check the work - he removed the thick washer and correctly tightened a couple of the other bolts. I put the brake discs and drive flanges back on, torqued them up and it rotates fine.

The offending washer is on its way back to the workshop to be used for educational purposes.

Thanks for the advice.

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10

Do you still have noticeable end float in that output shaft? If you do, there is still a problem.

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11

Richard there is absolutely no end float in the output shafts. By end float I’m talking about being able to pull the flange outwards or push it inwards. The bearings in the hub are supposed to be under pre load - that is they are tightened down to the point that they actually resist rotation. That is not adjusted after installation. You might have a small amount of rotational free play in the output shafts - that is normal.

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In addition - if you compare your photo to my photo - I suspect there is more to the issue than just the thickness of that washer.

13

Ok yes point taken. I guess two questions.

What is likely causing the erroneous end float - bearings not pressed home? Lack of shims? Something worse?

Secondly, does anyone have any recommendations for a UK based company i can call to get this fixed properly?

Thanks again

14

Hi Richard…one of the best guys in the UK to work on Jag diffs is Alan Slawson http://www.ajsengineering.com plenty of reccomendations on the UK E type forum for him

15

Richard - you might want to add your country of residence to your profile (e.g. the flag or a text line) as this can be helpful in avoiding useless advice.

Okay, you may still get some useless advice but perhaps not as much.

16

If it were me, I think I’d remove 5 bolts and pull one of those output shaft assemblies out. The cause of any end float should be immediately apparent, I would think. I certainly wouldn’t just install that diff as is and hope for the best.

17

Hello Richard,
The bearings originally used in your differential for the Output Shafts were Double Row, Angular Contact, Ball Bearings. The centre race was split and when assembled and with no load applied to the centre race, the outer ends of the centre race sat slightly proud of the ends of the outer race and there was a slight gap between the inner ends of the inner race. The gap between the inner ends of the inner race provided a predetermined, correct pre-load for the bearing. When the bearing was put in place and the nut securing the bearing in place tightened, the two halves of the inner race were drawn together until inner ends of the inner race came into intimate contact. This action put the bearing in pre-load. The correct, original bearing is shown in the following picture:

414444A-2
414444A-2683×561 61.8 KB

414444A-1
414444A-1675×564 57.8 KB

Unfortunately, this bearing hasn’t been available for many years. The bearing that is used in its place is a Double Row, Angular Contact, Ball Bearing, but the inner race is not split and therefore, there is no facility to pre-load the bearing and it is manufactured and assembled with no pre-load.

This alternative bearing has the same OD and ID as the original, but is 2mm narrower, 27mm as opposed to 29mm of the original. Accordingly, the After Market suppliers of parts for the diff, supply the bearing with two, 2mm thick spacers, one for the outer and one for the inner race, to make up for the 2mm narrower bearing dimension . These spacers should be placed on the outer side of the bearing. If these they are left out, you will end up with 2mm of Output Shaft End Float. Further, there should be shims between the inner face of the end plate, which doubles as the mounting plate for the brake caliper and the mating faces of the differential housing. Leaving these shims out will also result in end float of the Output Shaft.

I get quite a lot of my work, reworking repairs carried out by some describing themselves as experts. One of the largest Jag Parts suppliers in Australia and repairers of differentials, in a discussion relating to the setting of the Pinion Shaft pre-load, when asked how he actually measured the pre-load, stated " I check that with a Dial Indicator". Well, I hadn’t had a good day, and when I suggested that he was unique in the world, being able to measure less than no movement (my definition of pre-load to the lay person) with a Dial Indicator and that he was an idiot, he hung the phone up; go figure!

Regards,

Bill

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18

If Alan Slawson is not available give either ken Jenkins or rob Beere a call

19

Interestingly i had about 2mm of play in the output shafts… a second opinion showed the differential had not had the spacers fitted. Long story short end play is gone and there is now plenty of clearance between the bolts on the flange and on the case.

I’ll check recommendations here before getting other parts rebuilt.

Thanks for the advice - would likely have been a disaster i had just bolted it back in as was.

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