Subframe swap project

#101

The bolts seem to be M10X96. The nuts that Chuck included with the kit are a bit non-standard tho. I think that he got them from some aircraft parts supply outfit, which strikes me as a good approach to get a high quality fastener when you have an idea to improve upon an OEM fastener. The nuts have a wide bottom, like your old HS girfriend, so no washer is needed and they are taller than normal. And since they are taller, they have more threads inside. That being the case, maybe the fact that the bolt didn’t get to the last two threads in the nut is no big deal.

Over the weekend I finished up the job. I know I keep saying that, but this time it’s true. I undid the rtab nuts, put locktite on them and then fastened them back up. Then I put a dab of marking goo on each nut and each eccentric. that ought to tell me if something turns.

Then I filled up the brake reservior and bled the rear brakes. Finally, I put the exhaust back on. Putting the exhaust back on turned out to be a trial because one of the studs in the manifolds (to the downtube) had damaged threads. After many many attempts to get a nut on the stud, I ended up removing the exhaust again and going at the stud with a die. Because there wasn’t much room and the awkward angle prevented me from seeing if I had the die square, it was tricky. But I used up some good luck and the die fixed the threads instead of ruining the stud.

What I need to do now is go drive around the block a couple times. If there’s something completely screwed up, best I find about it now than when I’m loading the trailer next week.

#102

Jim - I listened to you. Last night I started my sub-frame swap and within a few hours had it ‘done.’ Today I’ll do the alignment and button everything up. Thanks for your tips and advice.[/quote]

I took the same approach and got everything to line up as it balanced on my floor jack. Thanks for the idea.

#103

Jim - I listened to you. Last night I started my sub-frame swap and within a few hours had it ‘done.’ Today I’ll do the alignment and button everything up. Thanks for your tips and advice.[/quote]

I took the same approach and got everything to line up as it balanced on my floor jack. Thanks for the idea.[/quote]
There’s a reason that Patton and a few others call me Yoda…

I’m glad that worked for you.

#104

I’m trying to figure out the 12 point nut conversion. Those would be used for the outboard eccentric nuts, but if they are 12 point, with the limited channel space between the sub-frame bushing and body, how to get a box wrench on the nut to tighten? :blush:

#105

The aircraft 12-point nuts are smaller in diameter than a hex hut, giving more room for the wrench. I have a couple of modified box end wrenches that I use, one for each side. Heating and judicious bending makes a wrench the fits into that confined space.

#106

[quote=“Ranger” post=55647] Hmm. So you unbolt the shocks at the bottom, remove the trailing arms and unbolt the CV joints from the diff. I guess the brake lines would need to be dealt with too. Then move the complete trailing arm and wheel assemblies off somewhere else. Then drop subframe and diff together. Is that how you mean?
[/quote]

Why remove the trailing arms? It’s actually pretty balanced as a whole assembly. I’ve dropped the assembly several times using a floor jack under the diff center and never had any balance/alignment problems. I don’t have the go fast aluminum subframe bushings, but the poly bushings line up easily.

#107

[quote=“FishMan” post=56432][quote=“Ranger” post=55647] Hmm. So you unbolt the shocks at the bottom, remove the trailing arms and unbolt the CV joints from the diff. I guess the brake lines would need to be dealt with too. Then move the complete trailing arm and wheel assemblies off somewhere else. Then drop subframe and diff together. Is that how you mean?
[/quote]

Why remove the trailing arms? It’s actually pretty balanced as a whole assembly. I’ve dropped the assembly several times using a floor jack under the diff center and never had any balance/alignment problems. I don’t have the go fast aluminum subframe bushings, but the poly bushings line up easily.[/quote]

I ultimately removed the subframe and trailing arms as an assembly.
A synopsis of removal would be:

-Separate brake hydraulics at the inner flex lines. Remove ABS sensors.
-Take E-Brake assemblies apart so you can disconnect the E-brake cables.
-Support the diff. Maybe drive shaft too.
-Separate drive shaft from diff.
-Bang subframe bolts up into body, carefully monitoring how you have everything supported at diff.
-Drop subframe, diff and trailing arms away as a single unit.

As an alternate plan, if the weight of the diff creates concerns about supporting this awkward assembly, remove the diff early in the effort. But when it’s time to put everything back together, putting the diff on the subframe early in the process is the way to go. This is because getting the diff’s top bolts on is a little tricky. Or you could put studs on top diff bolts and drill holes in the trunk to get to them.

#108

Add “throw E-brake components in the garbage” and I think you have a good synopsis…:slight_smile:

#109

I didn’t want to mess with the e-brake internals, so I just unbolted the cables inside the car at the handle and let the cables stay connected to the ‘hubs.’

#110

I had good success leaving the subframe studs in place. I am trying to figure out how it would be easier taking them out and trying to feed them back through the bushing with the subframe in place on a jack. Wouldn’t the subframe wiggle around? As long as both sides went up at the same rate, I got no binding.

But if Levie says to do it, it must work. I would be concerned about loosening up the knurled joint between body and stud if I removed the subframe repeatedly (not to imply that Ranger would try that project over and over and over and …)

#111

[quote=“Steve D” post=56438]I had good success leaving the subframe studs in place. I am trying to figure out how it would be easier taking them out and trying to feed them back through the bushing with the subframe in place on a jack. Wouldn’t the subframe wiggle around? As long as both sides went up at the same rate, I got no binding.

But if Levie says to do it, it must work. I would be concerned about loosening up the knurled joint between body and stud if I removed the subframe repeatedly (not to imply that Ranger would try that project over and over and over and …)[/quote]

If the diff is on the subframe, the bolts have to get knocked up.

I’ve always been careful about knocking things up. And I’ve found that loose usually works to my advantage.

#112

[quote=“Steve D” post=56438]I had good success leaving the subframe studs in place. I am trying to figure out how it would be easier taking them out and trying to feed them back through the bushing with the subframe in place on a jack. Wouldn’t the subframe wiggle around? As long as both sides went up at the same rate, I got no binding.

But if Levie says to do it, it must work. I would be concerned about loosening up the knurled joint between body and stud if I removed the subframe repeatedly (not to imply that Ranger would try that project over and over and over and …)[/quote]

If you are replacing the original OEM bushings getting the studs out of the way early is good since they can get bonded to the inner sleeve. If you already replaced the bushings once it may be less of a factor.

When I jacked my sub-frame up last weekend it went up perfectly flat and did not wiggle around with only one hand to supporting it. I used the bushing sleeves that stick out of the bushings a bit to align to the sub-frame and then the inner bolts just dropped into place.

I think the bolts just dropped back into there original knarlings when I gave them a quick spin and then they pulled the rest of the way in when I torqued them down.

#113

[quote=“Ranger” post=56439]If the diff is on the subframe, the bolts have to get knocked up. [/quote]My experience is different. Subframe studs stayed in place. Entire subframe assembly with trailing arms, diff, etc. all went up as one piece, guided in place by the studs. By me, a trans jack, a floor jack and some colorful language.

Given that most race car back seats are a complete bitch to work in, folks should know that your definitive statement is not 100% definitive.

#114

[quote=“Steve D” post=56438]I had good success leaving the subframe studs in place. I am trying to figure out how it would be easier taking them out and trying to feed them back through the bushing with the subframe in place on a jack. Wouldn’t the subframe wiggle around? As long as both sides went up at the same rate, I got no binding.

But if Levie says to do it, it must work. I would be concerned about loosening up the knurled joint between body and stud if I removed the subframe repeatedly (not to imply that Ranger would try that project over and over and over and …)[/quote]
If you can manage to lift the subframe perectly square and level the bolts can stay in place. But if you knock them out the subframe only has to be aligned for the last inch of lift, which is easier to manage.

Repeated removal & installation could wear the knurling, but if that happens weld a nut to the head of the bolts.

#115

[quote=“Steve D” post=56444][quote=“Ranger” post=56439]If the diff is on the subframe, the bolts have to get knocked up. [/quote]My experience is different. Subframe studs stayed in place. Entire subframe assembly with trailing arms, diff, etc. all went up as one piece, guided in place by the studs. By me, a trans jack, a floor jack and some colorful language.

Given that most race car back seats are a complete bitch to work in, folks should know that your definitive statement is not 100% definitive.[/quote]

I tried very hard to do what you describe. I don’t give up easily. I will stick with “it can’t be done” until I see someone do it. I will attribute your success to an anomoly in the same family as Easter Island and Stonehenge.

#116

[quote=“Ranger” post=56448] I will attribute your success to an anomoly in the same family as Easter Island and Stonehenge.[/quote]Is that more of an anomaly than my 2 1/2 year run with a motor we pulled out of an E30 that some 16 year old rolled over onto it’s lid? :laugh:

#117

It’s hard to evaluate degrees of anomaliness. But at the high end was the day in 1985 when some chick called up my roommate Andrew and told him “I’m getting married this weekend. The maid of honor and I are going out tonight. Bring your roommate, Scott or whatever his name is.”

#118

Here’s another way to skin this cat. http://www.e30tech.com/forum/showthread.php?t=105532

Notice the reference to dropping the center support bearing to get the drive shaft away from the rear subframe. I think this would allow a person to install the subframe the way Steve described above.

#119

What are we to assume happened that night in 1985?

#120

id just like to add my $.02… i just swapped my subframe in a total combined time of 10 hours within two days. i used none of the tricks mentioned in this thread. i simply put it all together on the ground and lifted it up into place slowly, went right in. i didnt knock out the pins, personally i think that is a bad idea but thats just me, or leave the diff off the subframe. i did however attach the rear shocks to the trailing arms so that i wassnt fighting their weight and then used a floor jack to raise the subframe up. maybe i got lucky…