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MG MGB GT V8 Factory Originals Technical - V8 axle pinion distance

Is there a way of setting the pinion distance without the special tools required.

I am re-building my axle and changing the ratio. I have done all the work and machining so far and have been happy with it so far, I am happy with setting the pre-load but this is the bit that has stumped me
Nigel Madagan

look at this web site. I am certain you can use the techniques on it for the B rear end
http://www.explorerforum.com/forums/showthread.php?t=144780
Richard Morris

here is my pattern

http://www.madagan.co.uk/webpic/pattern1s.jpg


in the picture the drive "face" is showing, heel to left, toe to right

I recon it is half way between bottom two right pics of the pinion too far away.

I would value any opinions, also how much "shim" should be removed

Thanks
Nigel Madagan

Hi Nigel,

I used the web page listed above to help me get my pinion depth set. One of the suggestions that I followed was to grind the ID out of the old inner pinion bearing about 0.001" to make it a slip fit over the pinion. that way I could dial in the exact amount of pinion depth a little at a time easily wihtout needing a bearing puller. I think I disassembled my diff about 15 times before I was completely satified with the pattern. I ended up with 0.002" thicker than stock on the pinion and 0.004" left offset on the carrier. With the slip on bearing I got it down to about 20 mins per disassembly and reassembly. Of course don't forget to replace the inner bearing with a new one when your done.

All the best,

Mark.
M Mallaby

Mark

Yikes 15, thats a lot, in fact there arn't that many different spacers. why so many (ie what problems can I anticipate)

Thanks
Nigel Madagan

I had never done this before and was overly cautious.
I paid particular attention to the pinion depth, I had 5 shims and tryed them all before settling on the a .211" shim. Each time you reassemble the unit (don't reinstall the compression sleave each time)just making sure that bearing load is OK (a little tight)and double checking the clearance took time. Once I was satisified with that I worked on the carrier offset. being that I had machined the carrier .215" off, the carrier shims were also probably not going to be correct. the carrier shims are NLA in the states so I to make them. The stock shim is .134 I made a set ranging from .128 to .140 in .002 increments. I ended up offsetting the carrier .004 to the left, this took about 5 tries. I probably had it right on the second try but wanted to be sure.
There are no real "gotchas" with this job. Just take your time. The end result is definatly worth the trouble. The 3.07 is very well matched for the LT77 and the V8. It makes the car "real" and 1st gear usfull.

Hope this helps!

Mark.
M Mallaby

Mark,

I've heard a few stories about the aftermarket 3:07 R&P being noisy, especially on overrun. I haven't heard anything first hand from someone who has installed one. So, what's the verdict? It's a bit of a pointless question I admit, since I have one on my bench ready to install. More a question out of curiousity.

Thanks, Steve Mc
Steve Mc

I have to really listen to be able to hear the rear end with the top up and the radio off. I can hear it but I would not call it noisy espcially when you consider how close we sit to the diff and how little body deadning material is in these cars. With the top down I can't hear it at all. My guess is the noisy ones don't spend the time getting the shims right. Being that we modify the carrier face (spend lots of time getting this right! the factory tolerance is +/- .007 I got mine to .004).

I drive top down 90% of the time but with the top up my cockpit is chok full of the cool sounds of the engine. I can hear the air cleaner sucking, the growl of the engine and the rumble of the exhaust. When I do my body work I intend to use copious amounts of Dynamat but for now the cab's pretty noisy in general.

All the best,

Mark.
M Mallaby

This thread was discussed between 05/04/2007 and 12/04/2007

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