Swapping rears this weekend, any suggestions/things to look out for?

[SadbutTrue]

Yeah, neither my dad nor I have any experience with this hands on, and were wondering what we should look out for. We are planning on reusing the current axles with the new housing/third member (going from 8 inch to 9 inch 28 spline). We have been told the axles and everything at their ends should come out as an assembly and bolt right back in. We planned on replacing the oil seals and gaskets...

What else should we look for? Do we have any room for error with the axles (ie if the housing is a tenth of an inch of, are we screwed)? Anything to be particularly careful of? Any tips for making it go as quickly and painlessly as possible?

 

[12sec67]

just go for it --- if you run in to any problems you'll have pleanty of help on stangnet!

 

[mustang70]

You shouldn't have any problems. Do you still have my number?

 

[STSFCTN67]

Be sure you get all the brass crush washers completly off before you start tugging on the pumpkin. Those washers can get really deep from being torqued down.

 

[iamadonut]

New oil seals and bearings maybe?

 

[SadbutTrue]

mustang70... i think i lost your number, feel free to pm it to me again (i might still have that pm though). I have the oil seals, don't have new bearings. Was hoping I wouldn't need em but I might go get them if mine look bad. What type of fluid would you guys run... do you need special gear oil for posi units? ANy additives?

 

[SadbutTrue]

alright... an update. We have the rearend in. The axle fit, while not flush like it was in the old 8 inch housing, is pretty good (the bearings stick out about 1/8 inch on both sides, which we think we can fix my cutting out some aluminum and using some extra gaskets). Other major snag was that our old leaf spring plates apparently won't work. The housing I'm now using for the 9 inch is a lot thicker than the one with the 8 inch, and is too wide for the holes in the old plate. Unfortunately NPD doesn't have this plate (the plate that the shocks and ubolts bolt to, that lies on top of the leaf spring) for a 9 inch rear (all they have is what I have, the 65-66 8 inch type). Where might I find one of these plates?

Other than that, it seems to be going well. The rear fits well on the leaf springs and bolted up well to the axles and feels very solid, and I don't think any driveshaft shortening will be necessary.

 

[mustang70]

Most people grind the holes in the plates to fit the u-bolts. Are they really far off?

 

[SadbutTrue]

thats what we ended up doing, no one on this planet has new plates it seems. We got the u-bolts on with some persuasion (in addition to being to wide for the holes, they were a tiny bit too narrow for the housing, so that made it really interesting... suffice to say, they are very tight, and not going anywhere for a while).

I also got your call, thanks a lot for the help.

unfortunately it looks like I will, after all, have to get my driveshaft shortened... gonna get that done tomorrow. the u-joint looks like it needed to be replaced anyway, and the yoke on the 9inch is bigger as well, so maybe this is a good thing.

Thanks