83 944

i have an 1983 944 and IIRC they do not make rear coilovers for the early cars yet. i found a set of 86 turbo banana arms and would like to put those on my torsion tube assembly.

is this possible to just swap the banana arms from my 83s steel suspension to the banana arms of an 86 turbo? or do i have to swap the whole rear end including torsion tube?

please help me i want coilovers! haha

thanks

M758

The arms will not fit on the 83 spring plates. The slots for arms are smaller on the spring plate. You need to swap the spring plate too. Which means you need to change the t-bars. They have to come out to change the spring plate.

ideola

I don't think this is correct. I have bolted up late offset alu trailing arms to a 1980 931 with no trouble at all, and I'm about to bolt 87 924S alu trailing arms (same as the 86 951 trailing arms) to a 1981 931. AFAIK, the late 924/931 torsion assembly and spring plates are identical to the early 944 stuff.

Here's a sequence of shots showing the 89 944S2 late offset trailing arms mounted to a 1980 chassis using the original spring plates, covers, torsion carrier, etc. Click images for higher resolution.





The one issue you WILL encounter, however, is that the early offset alu trailing arms require the longer half shafts, so make sure you get those; and you will also need to think about what you're doing with wheels, because the longer half shafts move the hub outward by ~21mm or so. So if you're running the stock 23mm offset 944 wheels with the stock 21mm spacer on your steel trailing arms, you can just dump the spacer. Otherwise, you have to make sure whatever offset wheels you're running will not be pushed outward too far.

M758

I tried to bolt up 87 924S (same as 86 951) trailing arms to my 84 944. The arms would not fit to the spring plate. If they did I would have not had to pull the t-bars and change the spring plate. Believe me I tried, but I would have had to cut the spring plate. So I had to change the spring plates to use the aluminum arms. I don't know what works on the 931, but it will not work on an 84 944. It was not big deal for me since I had a n 87 924S parts car with all the parts I needed.


You are correct on the longer 1/2 shafts. This however has nothing do with offset as both use the same offset. The steel parts use a spacer on the hub, but the aluminium ones do not.

ritzblitz

So does the aluminum one just delete the spacer and stick out 21mm more???

ideola

The longer axles are required precisely because the alu hubs are ~21mm further out, and it is directly related to wheel offset. As I noted, if he's using stock wheels with stock spacers on the steel arms, no worries, he can just use the same wheels without spacers on the alu arms. BUT if he's running a wheel other than stock that doesn't use the OEM spacer because it has a different offset configuration or width, he could run into trouble because the wheel will stick out further.

For example, I'm running Rial 9" rear wheels with ET11 on steel arms with no spacers on one of my cars. I have less than 1/2" clearance on the inside and even less on the outside. There's no way those wheels would work with the alu arms because they would stick out too far and would rub the fenders.


I was also pointing out if he gets the alu arms, he needs to get the matching half shafts regardless of what he does with wheels.

The 931 and 944 have the same spring plates. In retrospect, it's possible that I changed the spring plates on my 931 ultra wide body (pictured earlier) but just don't remember doing it...I did install new torsion bars...and PET does reference a 951 part number for the spring plates with the alu arms vs. a 477 part number for the steel arms.

ideola

Yes, and it's fine as long as you're using the original wheels, or wheels with the same offset as original. Where you'll get into trouble potentially is if you installed something like I did on the 941 (posted above, the red car).

ideola

One more clarification, just to be totally completely clear, we're referring specifically to the early offset alu trailing arms that came on the 86 951 and the 86-88 924S and comparing those to the early 924/931/944 steel-based trailing arms.

The late offset alu trailing arms have the hubs sticking out even further, and require even higher offsets...

ritzblitz

Yeah, I'm talking about the 86 aluminum arms. So basically, they are the same offset as the steel ones if the steel ones had the spacer glued on... correct?

ideola

Yessir!

83 944

so im just going to get the whole rear end of a 86 turbo. haha. and keep my 16x8 951 fuchs early offset

sounds less difficult to me at least!

ideola

Actually, once you remove the half shafts, if you can get the big mother bolts to break loose where the torsion carrier assembly bolts to the chassis, it's super easy to just swap over the entire torsion carrier assembly. The biggest challenge is not stripping the CV cheesehead bolts, but moreso, hope to God those big mother bolts haven't fused to the aluminum sleeve in the spring plate cover bushing! If they do, you're in for a fun time.

smokin_944

Ideola, if the cheesehead bolts are torqued correctly, 31ft lbs IIRC why would they be so difficult to remove?

ideola

It's not the torque that's the problem. There are two primary problems: 1) grunge in the bolt head; and 2) corrosion.

RE: #1, the bolts are completely exposed to the elements and are typically very badly caked with grease, dirt, grease, dirt, and more grease...to the point that you may not even be able to see the indentation where the triplesquare bit needs to be inserted. The huge mistake that most people make is that they do an inadequate job of cleaning out the bolt head before removal, and subsequently fail to get the triple square bit properly seated. In many cases, guys also don't have the correct tool, and attempt to remove these with an allen head bit, which is a huge mistake. The trick is to use the right tool for the job (a triple square bit); to very carefully clean out the bolt heads with a fine dental pick (and a few blasts of compressed air...wear goggles); and then seat the bit with several really good whacks with a hammer. This will wake the bolt, and also provide maximum engagement of the splines. If the bit doesn't seat properly, you WILL strip the splines out of the head, and make life absolutely miserable for yourself.

RE: #2, these bolts are treated with black oxide, which is not a good corrosion preventative. Again, because the bolts are exposed to the elements, they head of the bolt will often rust and fuse with the half moon clip. So even though the torque is relatively low, the corrosion will conspire against releasing the torque, and will exacerbate any mistake made relative to #1 above.

FWIW, if you're removing the half shafts, the bolts are supposed to be replaced. Do NOT reuse them. Also, make sure that you very carefully clean the threads in the inner and outer stub axles with several good shots of Brake Kleen (or something similar). You need to eliminate all traces of CV grease in the threads. Grease on the threads during reinstallation will prevent the bolt from maintaining proper torque, and WILL lead to the bolt loosening (which can put further strain on adjacent bolts and cause them to fail).

As an aside, you might be interested in this:
https://rennlist.com/forums/924-931-...ml#post7801872

M758

Plus the bolts installed from the factory with loctite in the threads. When I pull the joints I use blue loctite to keep them from backing out. You must break that bond when getting them loose. Here in Arizona we don't have corrosion to worry about.

Don't use red loctite as it will make them too hard to undo later.

It recommended to use new bolts all the time. Two reasons. One is they stretch during torquing. The second is grease. If you fail to clean them perfectly and clean the hole perfect they will back out. The factory manual says new bolts so you don't need to spend 10-15 mintues cleaning the bolts. Just charge the customer $5 for new bolts. However I have reused bolts from time to time so it can work. However for a street car where you may pull the rear end 2 or 3 times over 100k mile span just get new bolts. On my race car I tend to tear into things alot and don't mind checking these. In fact I put a white mark on the bolts an can use that to see if they have backed off at all. Since my race car is up on jacks most every track day at least for a tire change checkign CV bolts is very simple.

That said I have learned some this the hard way by having bolts back out on me. However this is mostly years ago.