Diff (crown wheel / pinion) setting jig
Discussion
Hi, New to the forum and this is the most relevant place I could find to post - sorry if its wrong.
I am having an axle rebuilt by my uncle, he knows how to do it but needs a jig / dummy setting device - does this ring a bell to anyone?
The diff casing is Salisbury 4HA from a Scimitar, the internals being fitted are Jag Powerlok and apparently to set the pinion shims right you fir the CWP set into a jig, measure etc etc.
If you have one you could loan or have the drawings / dims to make one I'd love to hear from you... Either reply by email or phone 01242 245962 / 07941 015484
Many thanks and all the best, Sam
I am having an axle rebuilt by my uncle, he knows how to do it but needs a jig / dummy setting device - does this ring a bell to anyone?
The diff casing is Salisbury 4HA from a Scimitar, the internals being fitted are Jag Powerlok and apparently to set the pinion shims right you fir the CWP set into a jig, measure etc etc.
If you have one you could loan or have the drawings / dims to make one I'd love to hear from you... Either reply by email or phone 01242 245962 / 07941 015484
Many thanks and all the best, Sam
Hi, The way I've seen this done is to bolt a length of metal to one of the output shafts, so that when the preload on the bearing is just right, the length of metal will drop.
This approach is based upon the correct torque that the diff needs setting up with. Cos torque is measured in lb/ft, if you get a 1lb length of steel, that is a foot long, this will try and exert a specific turning moment upon the output shaft. You will need to calculate the correct weight of the steel to use dependant upon how tight you want to set the preload. I'll try and find a slightly less ambiguous explanation on the web this afternoon.
You may need to refer to the diff manufacturer to find out what height you need to set the pinion to.
Once the pinion height is correctly set the crownwheel backlash can be adjusted, and then the mesh checked by applying engineers blue (or grease) to several of the teeth. The 'wipe pattern' should be approximately half way up the tooth. If it is too low then the shim thickness needs to be increased and vice versa.
>> Edited by fergus on Thursday 14th April 16:34
This approach is based upon the correct torque that the diff needs setting up with. Cos torque is measured in lb/ft, if you get a 1lb length of steel, that is a foot long, this will try and exert a specific turning moment upon the output shaft. You will need to calculate the correct weight of the steel to use dependant upon how tight you want to set the preload. I'll try and find a slightly less ambiguous explanation on the web this afternoon.
You may need to refer to the diff manufacturer to find out what height you need to set the pinion to.
Once the pinion height is correctly set the crownwheel backlash can be adjusted, and then the mesh checked by applying engineers blue (or grease) to several of the teeth. The 'wipe pattern' should be approximately half way up the tooth. If it is too low then the shim thickness needs to be increased and vice versa.
>> Edited by fergus on Thursday 14th April 16:34
Sorry to hijack, but vaguely on topic. I've just put a diff (Nissan R200 from a 200SX) back together, ended up putting everything back in as I'd taken it out - or so I thought. How much movement is acceptable between the crown and pinion before they engage correctly? I seem to have a noticeable (although not vast) amount of freedom when I turn the crown wheel either way before it contacts a pinion tooth.
Erm, hope that makes sense. I'm also hoping that it's acceptable and I haven't done anything stupind like putting the spacer shims on the wrong sides, as it's a sod to pull apart!
Cheers,
Rob
Erm, hope that makes sense. I'm also hoping that it's acceptable and I haven't done anything stupind like putting the spacer shims on the wrong sides, as it's a sod to pull apart!
Cheers,
Rob
Hi B19GRR, not that I'm any expert but sounds a bit scary to me...
Denisb and all, the extra problem I have with my 'project' is that its Jag internals going into a Scimitar GTE axle, therefore starting from scratch to make it actually fit and hence the need for the jig and not just a dial guage.
Not to worry, I will just keep on looking
Thanks for the feedback!
Sam
Denisb and all, the extra problem I have with my 'project' is that its Jag internals going into a Scimitar GTE axle, therefore starting from scratch to make it actually fit and hence the need for the jig and not just a dial guage.
Not to worry, I will just keep on looking
Thanks for the feedback!
Sam
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