Subframe swap project

#41

Nothing to grab for pulling. And nothing to push against.[/quote]

I edited my last post to elaborate on my idea. So the bottom part of the bushing is not larger in diameter than the inside of the subframe like every other subframe bushing?? I’d have to have a lip!!

Is the bushing one piece?? who did you order them from?[/quote]
T think they are AKG bushings. Each bushing is a two piece assembly with each part being a flanged cylinder. One part goes into the subframe from the bottom, the other from the top. Once installed there’s nothing to push or pull against with ordinary tooling.

One way that just occurred to me that should work would be to fill the bushing with a piece of rod and use two-jaw pullers on each side.

#42

They are AKG bushings. Scott…slide hammer…drill and tap a hole in the top bushing and use a slide hammer to pull the top bushing. CB

#43

I need a 3/4" tap and 21/32nd drill to do this. I found the tap yesterday but no one in town seemed to have the drill bit. I figure that if my favorite machine shop already has those tools, I can get it done for a lot less than the $90 + the drill bit that doing it myself is looking like.

#44

I need a 3/4" tap and 21/32nd drill to do this. I found the tap yesterday but no one in town seemed to have the drill bit. I figure that if my favorite machine shop already has those tools, I can get it done for a lot less than the $90 + the drill bit that doing it myself is looking like.[/quote]
I think there’s another way, see above.

#45

I need a 3/4" tap and 21/32nd drill to do this. I found the tap yesterday but no one in town seemed to have the drill bit. I figure that if my favorite machine shop already has those tools, I can get it done for a lot less than the $90 + the drill bit that doing it myself is looking like.[/quote]
I think there’s another way, see above.[/quote]
Is that a reference to “fill the bushing with a piece of rod”? If so, I didn’t understand that. Threading the bushing and putting a bolt in is clear enough, but what would hold the rod in place?

There’s powerful little lip on the bushing for a puller to grab. I don’t think a puller would get enough purchase. The puller’s fingers would just grab a little aluminum, and then the aluminum would deform when put under localized strain.

#46

I need a 3/4" tap and 21/32nd drill to do this. I found the tap yesterday but no one in town seemed to have the drill bit. I figure that if my favorite machine shop already has those tools, I can get it done for a lot less than the $90 + the drill bit that doing it myself is looking like.[/quote]
I think there’s another way, see above.[/quote]
Is that a reference to “fill the bushing with a piece of rod”? If so, I didn’t understand that. Threading the bushing and putting a bolt in is clear enough, but what would hold the rod in place?

There’s powerful little lip on the bushing for a puller to grab. I don’t think a puller would get enough purchase. The puller’s fingers would just grab a little aluminum, and then the aluminum would deform when put under localized strain.[/quote]

I spoke too soon. You mean two pullers, each with 2 claws, and on opposite sides of the bushing. Now I understand. They’d work against each other. That could work, but there’s still the issue of the very small lip to pull against. Worth considering tho.

#47

Ranger -

Try the French Military method.

Step 1: Admit defeat. Steps 2-5: Drill through the aluminum bushing, Sawzall that sucker apart, install rubber bushings, enjoy a nice glass of Pouilly-Fuissé.

#48

You could always undercut the bushing a bit with a dremal tool and a cut off wheel to give you a bit more to grad onto. That should not affect the busing when you reinstall.

#49

Try it. You’ll know very quickly if there’s enough lip to give the pullers a good purschase. I think there is if the pullers have 1/2" or wider jaws.

#50

An 1/8 of an inch is enough for the puller to grab.

#51

3/4" tap and appropriate drill bit were in the mail when I got home. Bushings are now out. Work continues.

#52

I wasn’t too concerned about swapping my sub-frame, but after reading this I’m a bit worried.

Would it be crazy to attempt to swap my sub-frame this Wednesday night (6pmish) before leaving for Mid-Ohio Thursday morning? Before reading Scott’s problems I wasn’t sweating it and thought it would be pretty easy.

#53

Re. attempting to swap out the subframe the night before the event. Not even I’m that optimistic.

Spent about 4hrs tonight on the subframe. Everything was hard. The aluminum sleave in the new rtab bushings have to be drilled out because it’s inner radius isn’t quite big enough. I made the mistake of attempting to drill them out after installing them. My vice isn’t very accesible right now, but it would have been better to drill some holes in a workbench and set the vice back up.

Sometimes it’s amazing how a simple little task can just turn into a complete goatsf**k. None of the aluminum cylinders were drilled out all that well, and one was such a complete cock-up that I damaged the shit out of it. The bastard got stuck on the drill not once but twice. I had a helova time removing it from the drill each time. And the effort put all sorts of heat stress on the bushing material, and some got mechanically stressed because the aluminum cylinder wanted to turn.

The way to overbore these aluminum cylinders right is these right is to use a lathe. When it comes time for you to do this, have Chuck Baader buy them for you and them bore them out before sending them to you.

The next problem was something weird with a camber eccentric. The eccentrics press against some “tabs” in the toe/camber kit and one of them was giving me real trouble. I couldn’t seem to get an eccentric on. Once I finally fought it into submission and got enough of the bolt thru that I might be able to thread the nut on, I found that the threads have been damaged in the fight. So now I get to repair the threads on the bolt.

I had to knock off for the evening. The back garage is so small that the only place to work on the subframe assy (rtab and diff are on it) is on the floor under the trunk of the car. That forces me to leave the garage door open. And as darkness closed in around me, it was just a matter of time before some thug stuck a 9mm in my ear.

I regret doing this. I had perfectly good bushings, I just had to suck up the fact that I couldn’t dial out 1/16" toe out. Now I’ve got bored out subframe bushings, poorly bored out rtab aluminum cylinders, with one of them pretty damaged, stressed rtab bushings, and some funky eccentric problem that I’ve not yet gotten to the bottom of yet. It is frankly hard for me to imagine that my new rear end is going to be stiffer than my old rear end.

#54

After I removed and refreshed my first rear subframe on the concrete floor in the shop I got smart. I built a work table large enough to get the whole assembly up off the floor for future projects. Attached some casters to the bottom and now I can move it around the shop as needed. We also mounted a vice to it. When your new garage is complete I’d suggest you look into something similar!! Built the table about 2 weeks ago and I’ve already used it about a dozen times!!

K.I.S.S. !!!

#55

For those of you that have done this project, is there consensus on which way the outboard rtab bolts should face? Should the adjusting nut be on the subframe bushing side so that the bolt (and therefore trailing arm) are removable, or should the nut be on the inboard side because maybe that’s easier to get to.

#56

I put mine in like oem… you can remove the trailing arms w/o removing the sub. think bent arm replacement.

#57

Yes.

When you have some time for sh!t to go all pear shaped, do it then. If you want to borrow my custom-made subframe bushing puller-pusher thingie, lemme know. Here’s the write-up.

bf.c link

#58

Good point on replacing the trailing arm. You could just drop the subframe a few inches to remove the outboard bolt and replace the traling arm. I have my bots installed with the nuts inboard; I believe they are much easier to access this way.

#59

Yes.

When you have some time for sh!t to go all pear shaped, do it then. If you want to borrow my custom-made subframe bushing puller-pusher thingie, lemme know. Here’s the write-up.

bf.c link[/quote]

Thank you very much Steve. I’ll shoot you an email shortly.

#60

When using poly or aluminum subframe bushings if you trim the bushing on the side that faces the trailing arm bushing you can remove the nut and eccentric plate w/o dropping the subframe. That also provides better access to the nut. Starter wrenches or bent box end wrenches make it easier to adjust the trailing arm eccentrics and if you use aircraft 12 point nuts things get even easier.