Opel GT Forum banner

1 - 18 of 18 Posts

·
Registered
Joined
·
54 Posts
Discussion Starter #1
I am in the process of rebuilding the front suspension on my car. The suspension is from a 71-72 opel gt. I started out thinking all I had to do was replace the spring but now the only parts I HAVEN'T replaced are the ball joints.
So, when I took the upper control arms off I noticed that the long pivot bolts fit loose in the tube through the shock tower. I replaced the rubber bushings with poly from OpelGT Source and now that I'm putting everything back together the play in the upper control arm seems excessive. The play is coming from the fitment of the bolt in the tube.

Just how much play is acceptable? Is there a way to fix this without having a shop remove the tube and welding in a new one? I imagine that replacing the tube has to be done very carefully to maintain the proper alignment so I suppose I can't just take it to any old machine shop. Brass sleeve bushings would seem to me to be a possibility but even that would be a major undertaking.

Any ideas??

Thanks, JH
 

·
Opeler
Joined
·
1,395 Posts
I am in the process of rebuilding the front suspension on my car. The suspension is from a 71-72 opel gt. I started out thinking all I had to do was replace the spring but now the only parts I HAVEN'T replaced are the ball joints.
So, when I took the upper control arms off I noticed that the long pivot bolts fit loose in the tube through the shock tower. I replaced the rubber bushings with poly from OpelGT Source and now that I'm putting everything back together the play in the upper control arm seems excessive. The play is coming from the fitment of the bolt in the tube.

Just how much play is acceptable? Is there a way to fix this without having a shop remove the tube and welding in a new one? I imagine that replacing the tube has to be done very carefully to maintain the proper alignment so I suppose I can't just take it to any old machine shop. Brass sleeve bushings would seem to me to be a possibility but even that would be a major undertaking.

Any ideas??

Thanks, JH
I have my front suspension apart now and have seen the same wear problem in that area. The wear on mine seems to be in the horizontal plane of the tube hole rather than in the vertical plane, allowing the ball joint end of the a-arm to move front-to-back.

There isn't all that much wear in the tube itself, but its effect is amplified out at the end of the ~foot long upper a-arm and thus it allows too much movement.

I have measured my tube and bolt and have determined that I can drill out the tube and install a slightly larger bolt and solve the problem. The largest diameter of the wallowed-out tube end is just under 1/2". So, yesterday, I ordered two 1/2" x 9", Grade 8 bolts and lock nuts at the local Fastenal store and plan to drill out the tube to 1/2", as well as the steel tubes in the bushings. I think that this will solve the problem since it doesn't remove much material from the tube ID.

If mine had been worn too much to salvage, I had planned to make an "overshot" tool from a metal cutting hole saw and mill over the OD of the tube and replace it with a new, beefier one. If the re-drill idea works, I won't have to bother with the tube removal
I hope what I'm saying makes sense to you and good luck!
 

·
Registered
Joined
·
384 Posts
I had the same problem. The bolt tube was only worn on the ends so I filed down a thin metal bushing to match the egg shaped hole and pressed it in to a tight fit. A little time consuming, but it took the play out nicely. I suppose brass would work, but might wear back more quickly.
 

·
Registered
Joined
·
54 Posts
Discussion Starter #5
I had the same problem. The bolt tube was only worn on the ends so I filed down a thin metal bushing to match the egg shaped hole and pressed it in to a tight fit. A little time consuming, but it took the play out nicely. I suppose brass would work, but might wear back more quickly.
I was thinking that it might be better to drill out the ends of the tube about an inch to 1.5 inches deep to accept a pair of sleeve bushings. That would place the tower walls at about the midpoint of the bushings. I'm assuming that most of the stress is in that area. The bushings could be pressed in with common garage-like tools and removed with a common puller. The bushings would wear down faster than the original steel, but they could then be replaced fairly easily. And that way everything else would remain stock. I'm really surprised Opel didn't design this better. This is an obvious wear point and it would make sense to put a replace-able bearing there.

I also found that once I torqued the bolt down there is no noticeable play. The control arm is "pinched" about 1/32". I can't feel any play but I'm sure there is still a bit when the weight of the car is applied. If I notice any effects while driving I'll consider going to the trouble of "fixing" the tubes in some manner. Perhaps the play in the bolt v/v the tube isn't that critical if torquing down on the bolt eliminates the problem. Maybe that's why Opel didn't design a replace-able bearing in there.

Keep the ideas coming. . . . .

JH
 

·
Just Some Dude in Jersey
Joined
·
14,139 Posts
I also found that once I torqued the bolt down there is no noticeable play.

JH
My first reaction to your dilemma was: "How did the sleeves wear out/egg out? They're usually locked down so tight you can't even get the bolts out.". I presume the bolts came loose under the previous owner's watch and, if left untightened, the play would cause all sorts of wear very quickly.
 

·
Registered
Joined
·
54 Posts
Discussion Starter #7
Yeah, but now I have a different problem. the reason I started on this whole project was that the leaf spring was so weak that the shape was completely distorted. The previous owner had lowered the front by cutting out one of the 3 leafs. That lowered the front all right, in fact one side was bottoming out on the rubber stoppers, but the spring ended up being shaped like a "W" and the front had a distinct negative camber. I replaced the spring with a new 1.5" lowered one from OpelGT Source. This actually raised the front end considerably, but with the new spring the camber switched from negative to positive on the passenger side and neutral on the other side. Switching the upper ball joint only makes the problem worse.
So, I replaced all 8 of the rubber bushings with new poly bushings also from OpelGT. I also replaced the shocks at the same time. The problem is slightly improved but with the upper ball joints in the inward position the camber is still off. I'm still getting neutral on the driver's side and positive on the other. I can't get any negative camber no matter what. And, the two sides are different. I've examined the front end as best as I can and I don't see any damage or obvious bends or dents, the shock towers look undamaged too.

I have no idea what else the previous owner might have done to the suspension to lower the front end.

When you check the camber should the lower control arm be in a horizontal position?
 

·
Just Some Dude in Jersey
Joined
·
14,139 Posts
It's pretty unlikely that you have something bent, but it is possible. Any sort of chassis bending is pretty unlikely because of the unibody design. Any bendage would cause all sorts of things to misalign.

That said, my previous car had a badly warped chassis. Not because of bendage, but because accident damage and the subsequent welding on of the right front corner from another car was done in accurately. The frame rail that the front suspension bolts to on the passenger side had been welded on slightly cocked upwards. The 1/4" deviation magnified to a 1" fender height disparity right to left in the front. The car leaned down at the right front corner. This caused the left rear corner to lift up by 1". Urg! I fixed the problem to within acceptable limits by putting shims of strip aluminum between the right front frame rail and the suspension. This lifted the right front and lower the left rear.

All that said, I had a different long time owned and driven GT that had an ever-present pulling problem towards the left into oncoming traffic. That car had been run under the rear crossmember of a tractor trailer that sliced the tops of the fenders off. That car had all new panels from GM, from the windshield forward, welded on by a GM dealership head mechanic. But the fact remained that the car had gotten squashed downwards in the accident. I replaced almost everything: The A-arms, shocks, bushings, springs, the rack, the steering column, the inner/outer tie rods, upper and lower ball joints, the brake calipers and rotors, and had numerous alignment attempts done. Nothing fixed the problem. Finally, the only thing left to replace was the front suspension crossmember. I blew out a disc in my back trying to get the lower A-arms bolts out unsuccessfully. I got a new, used, front suspension crossmember and the pulling problem disappeared. You could not tell by looking at the crossmember that it was bent. All I know is that replacing it fixed the problem.

These two examples, on my two longest owned/driven, Opels, that just happened to both choose me as their owners, are worst case scenarios. I can't say I've ever heard of any other member saying that they had misaligned frame rails or a bent front suspension crossmember. Therefore, it's highly unlikely that either of these 2 scenarios have befallen you. I just thought I'd throw these experiences of mine into the mix.

:sigh:
 

·
Member
Joined
·
1,183 Posts
Could be a bent steering knuckle (spindle) or bent upper ball joint. I’ve seen both of these happen. Bent ball joint was on a 1971 Kadett and the bent spindle was on a 1974 Manta. Both were caused by a side blow in accidents.

My best guess, though, is that the main suspension frame is either bent or has been modified. Good used ones should be easy to find.
 

·
Registered
Joined
·
717 Posts
After getting some reply’s on a different thread not supportIng the transverse spring eye bushing wear having much to do with my inside edge tire wear problem, I raised the car and put it on jack stands then placed the car jack under each spring eye, removed the upper ball joints, replaced the passenger side ball joint as it was loose. I found a gap big enough to add an extra washer between the inner bushing & the sleeve that goes through the crossmember on both sides.
507D7302-B0E4-494A-9932-9EDAD8652343.jpeg
I did a closer inspection and found the same problem being discussed on this thread with the upper control arm bolt wobble.
The cause seems to be what Gordo mentioned earlier, after 25 years of driving on my last front end rebuild, the nut on the long UCA bolt gradually worked itself loose causing the excessive wear on the crossmember sleeve.


I’m not sure what the clearance should be, and similarly to the previous post I can tighten the long bolts to 33 ft lbs and there’s no wobble but a good deal of clunking sometimes when braking at a stop sign with a good bit of forward inertia. I previously thought that it was the stock leaf springs which have been slowly coming apart until I discovered this. Along with the old squeaking poly bushings I’ll be replacing the spring with the upgraded sport version.

I got a price on a used replacement crossmember for a couple hundred bucks from OU so that route is an option. After I had the conversation with Todd, he even suggested that I hold on to my current crossmember, people who have severe rust problems will purchase and rebuild it.

I liked the idea JH came up with even better of having a short sleeve pressed in at each end by a machine shop. I’ll also call OGTS and get their input. Has anyone else done likewise and spent the money on having the upper sleeves inside of the crossmember rebuilt like that or perhaps a more durable method?

I’m also wondering if JH has found the solution for his problem?
 

·
Opel Rallier since 1977
Joined
·
1,474 Posts
Whoa.. that is bad wobble TC. They ought to be very snug. Are the bolts themselves worn?
Edit to add: BTW, why not just get some thin-walled snug sleeves, and then carefully drill out the ends of the tube with a bit that is the same size? What that will do is make a hole in the tube slightly larger than the sleeve by a few thousandths so they will be a hair loose. Then use sleeve retaining compound to put the sleeves in; they should NEVER move and will need heat to 500F to remove!

Here is a high temp sleeve retainer compound that should hold these in if the clearance between sleeve and tube is a few thousandthsl this is what is used to put cylinder sleeves in engine blocks. And there are probably other good choices of sleeve retaining compounds; these compounds are used to put sleeves into things like machinery bearing holes and saddles to fix them when they get wallowed out.

I would want the sleeves to go in 2" or so on each end. And don't put the bolts in until the sleeve retraining compound cures. Some excess will squeeze out and into the tube and need to be wiped out before it cures. This stuff takes an initial set in a matter of minutes
 

·
Super Moderator
Joined
·
13,362 Posts
This is typical in New England anyway. Rust is the cause. This crossmember hasn’t seen a road in 30 years BTW. So it didn’t take long for them to elongate back in the day.

426933
 

·
Registered
Joined
·
717 Posts
Whoa.. that is bad wobble TC. They ought to be very snug. Are the bolts themselves worn?
Edit to add: BTW, why not just get some thin-walled snug sleeves, and then carefully drill out the ends of the tube with a bit that is the same size? What that will do is make a hole in the tube slightly larger than the sleeve by a few thousandths so they will be a hair loose. Then use sleeve retaining compound to put the sleeves in; they should NEVER move and will need heat to 500F to remove!

Here is a high temp sleeve retainer compound that should hold these in if the clearance between sleeve and tube is a few thousandthsl this is what is used to put cylinder sleeves in engine blocks. And there are probably other good choices of sleeve retaining compounds; these compounds are used to put sleeves into things like machinery bearing holes and saddles to fix them when they get wallowed out.

I would want the sleeves to go in 2" or so on each end. And don't put the bolts in until the sleeve retraining compound cures. Some excess will squeeze out and into the tube and need to be wiped out before it cures. This stuff takes an initial set in a matter of minutes
Thank you for your suggestion MR. I’ll have to get another look at it once I have it out. That compound sounds like good stuff. I would think that you would need a drill press to set the new sleeves in straight but once that got done the rest looks easy as long as there’s enough surrounding metal.
An alternate idea I got from Gil today was to grind down the ends & tack weld on a reducer cap made from hard steel

860F56F1-6BB5-4749-99FC-5D7F1DE26294.jpeg

similar to the shim kits OGTS sells to mount the KYB front shocks (that’s where I got this pic from). I suppose the most critical thing would be to be sure to duplicate the length of the original sleeve overall and be certain it sticks out front and back exactly the same as the original to get proper caster with the shims. I’d have to get a machinist involved with either idea.
Since my GT has always driven straight I’m inclined to repair rather than replace. I’d sure hate to buy another problem.
Lindsay I go to Marshall’s all the time and can get lost for hours with all the stuff they have there, that’s exactly what I had in mind to start looking & see what they have before looking on the internet. I’d heard that bronze isn’t the best material to use for this application athough great for valve guides etc. but where there’s a lot of heavy weight, perhaps not the best metal to use? There’s a good chance that I can find a sleeve there in steel, or just a solid round 3/4” or so diameter that can be drilled out.
 

·
Opel Rallier since 1977
Joined
·
1,474 Posts
There are a lot of grades of bronze but they all are going to be softer than the bolt. Bronze bushings were used with older kingpin setups, but they were always made to be able to drive then out and drive in new ones, and there were grease fittings to regularly lube them. The nice part here is that this takes only lateral loads, not the car's weight. But the whole idea of bushings in the present tube is going to mean very thin-walled tubes.

Interesting idea on the welded-on outer bushes. But it seems like you will grind off all the weld that is hold the inner tube in place....??? Why not just cut off the ends, grind out the end welds, knock out the old tube and weld in a new tube? I am assuming that the present tube is located by a snug hole drilled in the subframe, but you could make some temporary locating devices before removing the old tube.
 

·
Super Moderator
Joined
·
5,726 Posts
To not make too small a point of it, when the upper control arms are properly assembled and tightened, THE UPPER BOLT DOES NOT ROTATE INSIDE THE UPRIGHT TUBE. The bolt is held stationary against the tube, which is IN COMPRESSION, as are the inner sleeves in the UCA bushings. The OEM caster shims are serrated on both sides to ensure that the tube and inner sleeves of the UCA bushings stay locked together.

On OEM bushings, the rubber flexes between the inner and outer sleeves, which allows the required rotation of the UCA.

On polyurethane bushings, the bushing is held secure to the UCA, and the bushing rotates around the inner sleeve to allow the UCA to move. That is where the silicon lube should be placed.

If an upright tube has become worn, as several of these photos indicate, it was because the UCA was not properly assembled or tightened.

To repair the tube, the inner hole merely needs to be sufficiently tight to the bolt as to not allow excessive lateral movement. A brass bushing will NOT be better in that it allows the bolt to rotate with less wear. THE BOLT SHOULD NOT ROTATE IN THE UPRIGHT TUBE. A brass bushing might allow the bolt to not become seized inside the tube, which is what typically happens. So either a brass bushing, or a steel bushing may be used to repair the tube.

Just ensure that there is sufficient grease or anti-seize between the bolt and upright tube so that they do not seize together in the future.

HTH
 

·
Opel Rallier since 1977
Joined
·
1,474 Posts
Now you have got me to wondering of a thin bushing inside of a thinned-wall tube is a good idea.... Unless they are locked together (with something like the sleeve retaining compound, or maybe red locktite), they might want to crush, not just with the clamping force of the bolt but the occasional extra force that wil be seen on the front side in particular (like when hitting a pothole).

Glad you mentioned the lack of rotation; I know it in the back of my head that the bolt does not rotate but it was not in my immediate thinking. I was thinking of the crushing wear that bronze sees in kingpin use; I should have ignored the grease factor.
 
1 - 18 of 18 Posts
Top