[Kristi]

How hard/expensive would it be to find a rearend for a 72 GT? And any guesses on what labor would be to have it installed? I'm still diggin that Opel in Boston, but the new rearend thing worries me. That is one thing I know nothing about. (one thing????)\

The Boston car needs a new rearend, a new headliner, and a new radio. If the rearend isn't that expensive I can handle the other stuff no problem.

 

[Stanley_P]

I have a used rear end off a 71 GT that needs cleaning up, brakes checked and new rear end grease. Its yours free if your coming thru Kentucky......If not, check with local junk yards and find a 71 to 73 rear end, from what I understand the older rear end are no good (different bearings in them)

A new headliner is nothing to put in you could do it yourself. OGTS is about $85.

Radio is no problem you can get a good stereo anywhere and do that yourself.

Stanley_P

 

[opelgt722002]

headliner

You do have to remove all the glass to install the headliner. Sometimes that will mean replacing all the rubber around the windows.

 

[opelbits]

You should be able to have the rear end put in for less than $300, as long as you don't go to Dobb's, Firestone, etc.. Any more than that and I'd question it. Mind you, that's not including the cost of the rear end or putting new wheel bearings and seals (don't forget the pinion seal). Bearings if you need them, seals definitely. Shouldn't add much cost and you don't find out that the thing won't hold gear oil after spending all the money to put a new axle in.

 

[oldopelguy]

Option

I'mm 99% sure a Kadett rear axle will bolt right in too, and they might be easier to find in local junk yards. If you do get a whole new rear end make sure you get one from a car with a 1900 and not a 1100, for the better brakes and bearings. If you find a Kadett wagon, get the rear anti sway bay too, you will appreciate it later.

Or alternativly, I could just bring you one of those too. I think I have 3-4 rear ends laying around. You would still be advised to have them gone through, but you would at least have one.

One thing to consider is that the torque tube "donut" that routinely fails on Opels is frequently diagnosed as a rear-end problem. It has many similar indications, but is alltogether within your realm of fixing ability.

 

[Kristi]

Hmmm ok ... all very good advice. And much more that I expected as far things I needed to know! Thanks for that everyone. As far as the possible misdiagnoses, how would I find that out? Just buy the car and see? The guy said he already rebuilt the rearend once and says "its ok up to highway speeds but after that it would need replaced." I'm just not sure what that means....

 

[Kristi]

Oh and I forgot to say he said it comes with sway bars...

 

[Jason73GT]

Difference Between 72 and 73

Weren't Manta rearends used on the 73 GT? How would this affect the swap if taking from the 73 and putting it into the 72? I've got both a 72 and 73 and will be facing this question myself soon.

 

[RallyBob]

Manta rear ends are different from GT rear ends. They're about 2" wider, have different swaybar links, and have different shock and panhard bar mounts. The GT used one type of rear axle from 1968-1970, and another from 1971-1973. This coincides with the Kadetts of those same years, so they are indeed interchangeable (but springs are different).

However, the 'guts' of the 1971-1973 GT are interchangeable with those of the 1971-1975 Manta, except for the axle shafts themselves, as they are longer. Bearings, differentials, ring/pinion, etc....they all swap.

The only discrepancy with my statement above is that the Manta Rallye and Kadett Rallye had a 3.67 ring and pinion, while the GT and regular Manta had a 3.44 (some Kadetts had 3.18's). So, in this case, the differential from a 3.18 and 3.44 is the same, but the differential from a 3.67 (also fits 3.89, 4.22, 4.75, 5.13, 5.28 BTW) is not interchangeable with the differential for the 3.18 or 3.44 final drive.

Bob

 

[Kristi]

Hide & Seek

Ok, back a few weeks ago I mentioned my GT seller told me I may need a new rear-end. He said that it was "ok up to highway speeds but I wouldn't push it" He just rebuilt the rearend last spring but said at highway speeds it has a "whine" to it. Oldopelguy mentioned it may be the "torque tube donut" as that is often misdiagnosed and is much more easily fixable. Only thing is I cant get the poor guy to tell me what the heck that means or how to know which it is?? Any help from the peanut gallery?? The only donuts I know about are jelly....

 

[kwilford]

Rear End Whine?

Kristi, did you ever get an answer to this? It was during the summer, and a bunch of folks were on vacation, and Gary was messing with the program, and I am now doing a bit of housekeeping...Or did you buy a different GT?

The whine you describe is not likely related to the torque tube donut. That item is a rubber cushion ring around the central joint bearing, between the "torque tube" and the drive shaft. If the donut gets perished (which they do) it manifests itself in a "clunk" when you accelerate, as the drive shaft windup causes the shaft inside the torque tube to wack against side of the tube. Fixed by replacing the donut, or adding some "filler" (such as old vee-belts) around the outside of the donut.

The whine could be the centre bearing, or mud between the bearing and the metal shell that surrounds it. Or a bad U-joint. Or a bad wheel bearing. Or it could be the differential.

If the PO "rebuilt" it without doing it properly, that might cause a whine, or at least have not corrected it. Some folks think that a "rebuild" is defined by replacing the seals and maybe some bearings. But unless he correctly replaced such items as pinion depth shims, the pinion collapsible spacer, or even the axle shims, the differential is probably chewing itself up as you drive. Or you may have a bad bearing (of which there are a number). Or a worn ring gear or pinion gear.

Let us know how you made out.