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I'm finally to the beginning of putting my '68 chassis back together and could use some advice on getting the differential installed. The crossmember has new bushings installed and I bolted it to the top of the differential. The differential is from a '73 and the lower front mount bracket I believe is a '72. In the pics below, I have the diff raised to the point where the crossmember bushings are 2/3 into the sombrero. The hole in the lower front mount, snubber bushing, and frame bracket are not aligned. Is this normal and just has to be "persuaded" into place with the bolt or have I created a problem with the combination of different year parts? Thanks in advance for any help or suggestions.
I know that when you go to change that front cushion the diff will try to tilt up at the front and makes it hard to get the new cushion in place so it must be pre-loaded somewhat..
68 did have a different front bracket than 69-79 but I don't know what the difference was, might have been the length
M
quick look around and it seems the 68 early didn't have the reinforcement on the side where the holes went through but I don't see any mention of a length different
M
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I think I bolted my front on first, then lubed the sombreos and pushed the diff up into them. I then used studs,, then nuts and the heavy outside plates with nuts on the outside to sandwich it all together. I dont think the threads are strong enough to pull it together with bolts.
Checked my pictures (they replace my fading memory) and it looks like I had the crossmember hanging way down and got all 3 bolts in and then brought the crossmember up into place and then tightened the pinion bracket
here you can see how far down it was when all three bolts went in
M... Thank you for your thoughts and the trouble to look back through your pics for that info. I will give it a try and see what happens. I was thinking about pulling the rear pin out of the bracket to allow it to tilt and align better with the hole but not sure it would move enough. The snubber bolt would definitely go in at an angle but I was afraid to try pulling it together that way without asking.
Rescue... Thank you as well for your response. I don't have the studs or the plates but will consider that if I can't get it together without.
By the way, when I got the car it had no drivetrain which is the reason for the mismatched parts. I can't take credit for the frame or diff. David Howard got me in touch with the shop he uses for his frames. They (and their powder coater) did a great job. Bair's restored the diff for me 2 years ago. They have the TA's now and hopefully they turn out as nice.
Thanks again guys! I will reply back with the results.
I did use anti-seize on the two large bushings before attempting to install the crossmember. Unfortunately in my situation it was not enough. Dropping the crossmember down with the two bolts just started and trying to get the pinion bolt started did not work. I was very close to getting the nut started but need a little more bolt length. I gave up last night and threw the snubber cushions in the freezer to see if that might get me just enough room to get the nut started. Will try again tonight.
It could possibly just be me. I'm still learning as I go.
In your pic below, were the crossmember bolts already tight drawing it up to the frame? If so, I misunderstood last night. I was thinking the bolts had to be loose while attempting to get the third bolt (pinion) started. Once all three are started then proceed with tightening all three up.
I have removed/replaced several diffs in different frames and always had the crossmember on the frame first when replacing .
I would try loosening the 4 diff to crossmember bolts as well after getting the 2 bolts in the sombrero's . Sounds like doing that would give you enough wiggle room to line it up.
My 69 crossmember bolted straight into my rust free 78 chassis and allowed my 75 year diff to attach trouble free !
I started the 2 crossmember bolts enough to suspend it, then dropped the pinion bolt down through the bushings and basically tilted the diff up enough to start the nut (less the washer as I recall and then tightened the two crossmember bolts up that pulls the diff up snug against the cushions, remove the nut, install the washers finger tight as they were in that photo when I was installing the drive shaft. Afterwards tightened down as in the other pic.
That was with fresh bushings, last time (two years ago) they had a bit of squish so it was a little easier as I recall
M
Thank you Bazza for the info. Nice to know the mixed year parts should not be the problem.
I ended up using a combination of all the input above (loosen the 4 bolts on top of the diff, tighten the two into the sombrero, pull up on the bracket at the pinion to get the nut started, torque the nut to compress the bushing, then go back and torque the two sombrero bolts and four crossmember to diff bolts) and was able to get the differential into place.
Success!! The only thing I see now is there is still approx. 1/2" gap between the top of the bushing and the sombrero mount. From what I saw in searches this is common and seeing as how I don't have any weight on the frame yet I will let that go for now.
Thanks again all for the input and suggestions. Much appreciated!! Bring on the next challenge
Hi guys, this is René from Germany. I am currently facing a "strange" situation... I wanted to replace the diff front bracket rubber bushing but there is so much preload on the bracket I need an extension/metal bar to move/tilt the diff down at the front bracket to get the rubber out. Is that normal? In addition, it looks like my diff is tilted/pointing downward towards the front of the car. Should it not point upward?
Looking forward to receiving some comments from you!
Hi Rene, I probably don't have enough experience to answer your question so hopefully others will respond. I am putting my car back together from mostly pieces so I'm not sure what is normal for them but in my case the bracket was too far toward the ground which made getting the nut started difficult. I had to squeeze it upward to get enough threads of the bolt exposed to start the nut.
Can you remove the front bracket bolt that attaches the bracket to the bottom of the differential? If so, maybe you could rotate the front of the bracket downward enough to get the bushing out?
Hi TM, thanks for your response. What you describe seems to be the opposite situation to what I have. You obviously have the front support bracket pretty much down so it is hard to get it upward to get bolt and nut engaged. At my end it is just the other way round... the front support bracket has so much upward preload that I need to force it down to get the rubber bushing out... very strange, isn't it!?!
I understand which is why I asked if you could remove the front bolt (the forward most of the two that run left to right side of the car through the bracket and differential). I think if you do this it might allow the front of the bracket to swing down enough to slide the bushing out.
Differential install help?
The only thing I see now is there is still approx. 1/2" gap between the top of the bushing and the sombrero mount. From what I saw in searches this is common and seeing as how I don't have any weight on the frame yet I will let that go for now.
