Diff pinion bearing - help required please

[Knockwurst]

All,

I am rebuilding my diff and have come across a problem. The front pinion bearing that I have ordered from Rimmers is too small. I have spoken to Rimmers who were very helpful. They suggest that their part is correct and believe I may have a TR6 diff.

I ordered part 134070 which has an outer diameter of 57.12mm
The old bearing has an outer diameter of 61.99mm
The inner diameter appears to be the same on both bearings.

I have changed all the other bearings in the diff with standard Stag parts from JP and Rimmers and eveything else fits correctly, including the rear pinion bearing. I assume the diff ratio is correct, as the speedo has always read correctly and I seem to get around 20mph / 1000 rpm from a BW35 trans.

Can anyone help? Rimmers suggest cross referencing the diff serial number and see if this a TR6 diff, then order part number 100422, which has an outer diameter of 62mm.

I was hoping to get the diff put back in the car this weekend

Thanks in advance for any advice or help offered

Simon

[LAMBRETTLAD]

At first thought 61.99 is so close to 62 ,and as both have the same internal diameter,going with rimmers suggested answer is the way to go ? Good luck

[mole42]

Simon,
Don't forget that these diffs were built with imperial bearings, so you need to think in inches! The outer diameter you have is 2¼" the old one is 2½"

Does your diff have a Nyloc nut on the nose or a castellated nut with split pin? The diff bearings changed when they changed from shims to collapsible spacers.

I have all the correct bearing numbers if you need them.

Richard

[Knockwurst]

Simon,
Don't forget that these diffs were built with imperial bearings, so you need to think in inches! The outer diameter you have is 2¼" the old one is 2½"

Does your diff have a Nyloc nut on the nose or a castellated nut with split pin? The diff bearings changed when they changed from shims to collapsible spacers.

I have all the correct bearing numbers if you need them.

Richard

Richard, it is the collapsible spacer type with nyloc nut. Sorry, about the metric / imperial, I seem to choose metric by default!

The correct bearing numbers would be good, then I can cross reference the Timken bearing that was fitted. Rimmers only list 134070 for the Stag though.

I've ordered the 100422 part anyway in the meantime, so that I have it to hand if it is the correct part.

Thanks
Simon

[mole42]

The Stanpart number 134070 should be correct for the collapsible spacer pinion, Timken part number: Outer 15245 - Inner 15100SR which is 1.000" (25.4mm) / 2.440" (62.0mm) / 0.750" (19.05mm)

I don't have the other numbers to hand but I think you will need the Timken bearing detailed above. If the Rimmer's one has different part numbers, they have sent the wrong one.

Richard

[mole42]

Further bearing numbers, these are the correct ones for the early shim-adjusted Stag diff pinions:

1" (25.4mm) x 2.25" (57.15mm) x 0.765" (19.43mm) M84548/M84510.MB

1.25" (31.75mm) x 2.8438"(72.23mm) x 1" (25.4mm) HM88644/HM88610.MB

It seems as though you have a bearing for an early shim-adjusted pinion.

[Knockwurst]

The Stanpart number 134070 should be correct for the collapsible spacer pinion, Timken part number: Outer 15245 - Inner 15100SR which is 1.000" (25.4mm) / 2.440" (62.0mm) / 0.750" (19.05mm)

I don't have the other numbers to hand but I think you will need the Timken bearing detailed above. If the Rimmer's one has different part numbers, they have sent the wrong one.

Richard

Richard, I have checked the old Timken bearing and it is Outer 15245, inner 15100SR as you suggest, but I think this relates to a TR6 bearing p/n 100422, rather than the Stag bearing 134070.

I have been cross referencing all the other parts on the Rimmer site between a TR6 and a Stag and all bearings are the same, except this one. I also note that my diff housing is marked 305815, which is also listed as that for a TR6.

So, I hope that the 100422 bearing I have ordered will work!

Thanks
Simon

[jbuckl]

Great information from Richard

[mole42]

Reviewing this, I think Rimmers have sent you a pinion bearing for an early shim-adjusted diff. The size looks like that one. They do make mistakes sometimes :-)

I don't have my parts book with me just now to check the earlier part numbers, but the Stanpart number you ordered (134070) is correct for the collapsible spacer diff (15100/15245), the bearing they sent you is not correct.

I don't think the TR6 diff will be use different bearings.

Hope this helps,
Richard

[Knockwurst]

Great help, thanks everyone. I'll let Rimmers know that they should be specifying two different bearing types, depending on which spacer is used.

The difference between the two is here

image.jpg

[LAMBRETTLAD]

Well done that should save others time and effort ,if Rimmers action your suggestion