can anyone tell me the distance from the axle centreline to the rear face of the diff.( i.e.the rear gasket face.) Dana 36

I need this info to set up my new gears properly.

cheers

john

 

I don't have that dimension, and I doubt it is carefully controlled. What ever it is, it wouldn't affect the relationship of the ring gear to the pinion. Also, what ever it is, YOU have no way of changing it, short of having your carrier housing machined... and for WHAT reason? Dana references from the end of the pinion to the center of the ring gear.

RACE ON!!!

 

quite right CFI-EFI, Dana does reference from the pinion to the centre of the ring gear - but how do I measure that to within .001 (ish) as specified???

I reckoned I could measure to the gasket surface pretty accurately and subtract the gasket face to axle centre.

hope this makes sense...

otherwise - how do I measure to the axle centre?

 

I understand it, but it doesn't make sense. As I said, the dimension you are seeking isn't as closely controlled as you need to accurately set your pinion depth. The special tool you need has a fixture that centers itself in the side bearing bores, and a micrometer to measure to the head of the pinion. This is ONE reason gear setting is best left to those in the business. There MAY be hope, however. Are both your new and old gear sets, Dana? If so, get me the numbers etched into the backside of the two pinions. Otherwise, how is the depth of the new pinion expressed?

RACE ON!!!

 

Thanks for you replies CFI-EFI.

The new gearset is Richmond, and the pinion depth setting is marked on the end of the pinion as 2.554.

The old set is original GM 2.59, and there are three markings on that pinion -

880
+3
An indecipherable squiggle (somebodies initials??)

I think you may have already given me the answer I don't want in the two words "special tool"

It wouldn't be so bad if the bearings weren't such a pig to get on and off, so trial and error is a poor option.

john

 

Let's see what we can do with that. The 880 is a match number. You will see that same number etched in to the ring gear. That merely means that the ring gear and pinion are a "matched" set and that they belong together. The +3, means that the pinion was matched with the ring gear at a distance of .003" greater than the "Blueprint" dimension. The blueprint dimension is. "2.565", therefore, Your pinion should have been set at 2.568 from the centerline of the ring gear.

With your new set spec' ed at 2.554, it would have a marking of, "-.011" if it had been made by Dana. The pinion in the new set must be set up, .014" closer to the ring gear center than the old one. Remove, clean and measure the individual shims from behind the pinion, rear, bearing cup. Now prepare a shim pack that is .014" thicker than what you removed. This SHOULD be the correct thickness. Of course you are relying on the accuracy of the original shim pack. Once you have everything installed, mark the ring gear and check for a proper tooth pattern. If it is off, you may have to change the pinion depth, and/or the backlash. If either the pinion depth or the backlash are off a little, it may howl. If they are off a lot, you'll be buying a new gear set, soon. I hope you're saving money.

RACE ON!!!

 

Thanks for that.

money is no problem to me. I haven't got any- how could it be?

thanks again CFi. I will proceed with your info and recommendations

 

Let us know how it works out for you.

RACE ON!!!