Der Treiber

What is the prevailing school of thought on re-fastening the torque tube bearing carrier halves to each other? The DarkHorse video dude, while that was a nice video for a lot of reasons, I just felt like there has to be a better way. This is a 90 S2, but it still has the split carriers. Are there other, newer carriers that don't have to be joined together? Appreciate your input. And no, I don't have the budget for the BlackSea stuff...wish I did.

Van

Pop rivets.

Constantine

Our products will not work in your split torque tube.

We have found the newer non-split factory carriers in the 944S2 and 968
split tubes.

Most hand operated pop-rivet guns need to have their heads ground down to be able to get into the space of those bearing carriers to install the pop rivets. Use steel pop rivets for longevity, not the aluminum ones.

Cheers,
Constantine

pfarah7

This is what I did when rebuilding my spare TT:
-Grind down rivet heads as shown.
-Stagger rivet insert arrangement so three heads will be on each side.

Tiger03447

You also may have to reshape the nose of the pop rivet tool you are using to get down far enough into the groove to get a good bite on the rivet shank. I had my buddy with a lathe turn the nose down for me. You might be able to do this with patience and a dremel though..

Tiger03447

Constantine is right about the pop rivet nose. I should have read his reply more closely. I also used ground down reinforcing washers on the backside of the pop rivet for better engagement and upset. I would like to see how the newer carriers are put together, however...any pics anybody? Somehow I feel there has to be a better way..BTY are you going replace the delrin inserts as well? If so, you may have to fabricate a tool (socket?) to help with the insertion...I used a small 1 ton arbor press to pop mine in with...hope this helps some...

Constantine

Those inserts are not made of Delrin.

Delrin is an incorrect material for this application.

Cheers,
Constantine

Tiger03447

OK..I stand corrected..are they nylon? What kind of material seems to be the correct one? I ordered a set for my bearing from an outfit up in Vancouver, I think..They were the right size and seemed to fit up OK. Did I do wrong here? My TT is all assembled, waiting for re-installation...tell me now, before I eff it up...Thanks.

Constantine

https://rennlist.com/forums/showthre...errerid=167193


Hi Tiger03447,

The above email link is of a thread done by "Paulyy" on the 944 turbo forum. In this thread he discusses the problems of certain rebuild methods to include using delrin bearing inserts.

Since we sell our own torque tube rebuild products, thought to provide this thread to you, and anyone else following along, to allay the problem of us seeming to discount a rebuild method for our own benefit.

If the link doesn't work you can also do a search on the 944 Turbo forum under "Paulyy" or "torque tube rebuild."

Cheers,
Constantine

Der Treiber

This forum is so awesome. After getting Van's response I did a bunch of research on pop rivets, because it's just something I hadn't done before. I settled on a tool, decided I was going to have to grind down the tip to fit in that 6mm wide valley, and started playing w/ sleeve extensions on the rivet to help get in there as well. Also figured out rivet size and everything (putting a 5/32" rivet in a 11/64" hole), and decided on stainless steel w/ stainless mandrel rivets for strength and since I just didn't want anything to rust. Can't use aluminum because the carriers are steel.

Got all that on order and decided to check back here and then saw all this great info that confirmed my plan. Thx!

Constantine, yes I am a bit confused on this split carrier thing, as everything else I have read so far seems to indicate that my 90 S2 should have the newer, one-piece carriers, so somewhere in the PO history, those must have been swapped out for some reason. Probably contributed to their failure...the bearings were straight in the TT, but the 3 of the 4 bearings were dry and worn out, 1 basically didn't spin by hand, so it was past time.

pfarah7, great pics, and nice job, btw! I hope mine turn out as well as that....looks like you may have smoothed them over w/ a dremel or something after the rivet.

The guy in Canada w/ the delrin inserts wants more than I am willing to pay, and my existing inserts look perfectly fine, so I think I am just going to re-use those, unless anyone has a good argument as to why I should not. Tiger, I have a hydraulic press, so shouldn't be a problem getting those inserts in.

One last question. I measured the driveshaft nub, as I have a similar situation as another recent poster who said his driveshaft nub had some play on the pilot bearing.

https://rennlist.com/forums/924-931-...-fork-pin.html

I don't have any play, per se, but the old pilot bearing easily slips on and off the shaft nub. It appears to be a 15mm ID bearing, and my shaft nub measures between 14.91 and 14.96, depending on where you measure it. Is that about right or too loose? What's the appropriate amount of tolerance before a new shaft should be considered?

Tiger03447

Should be OK..it isn't a press fit. Just lube the pilot bearing needles well, before the assembly. Has to be better than mine, which were dry and rusty. The only problem I had with my TT besides taking it apart was getting the shaft back into the TT..Use a wooden block on the spline end and whop generously with about a 3 lb or better hammer. After you get past the first couple of bearing it should self-align. When putting in the second carrier bearing, be sure to get it behind the screw openings for the shifter bracket. Not cool to run the screw into the carrier bearing. That's about the right place for the #2 bearing..Constatine was kind enough to show me how they placed the bearings on the shaft and their placement within the tube. I think he uses WD-40 to lube the interior of the TT prior to replacing the carrier bearings. I used Wal-Mart KY jelly on mine..since it's water soluable, I didn't want to deteriorate the rubber rings with an organic lubricant. Just slathered it on a large cloth and poked it through with the threaded rod. several times. shine a light inside to see how you're doing..I put the bearing carriers inside the tube then put in the shaft. I'm sure there are several other ways to do this..Just don't hammer on the pilot bearing nub, unless you use a wooden block to soften the blow and keep the nub intact..That's what the taper on the big end is for..to aid in the shaft insertion..I guess.Hope all this rambling helps some.

Constantine

We do not use WD-40 to place our products into the torque tube. WD-40 could migrate into the bearings and wash out some of the grease causing premature failure.

Delrin inserts are too hard to grab and support the drive shaft correctly within the bearings. The drive shaft will start spinning within the delrin inserts and start wearing away the drive shaft coating exposing the metal to corrosion. The delrin inserts ID will also enlarge over time which exacerbates the felt driveline vibrations and possibly cause poor clutch engagement in the future.

Old insets are worn out and re-using them can cause similar problems. They can also fragment as the drive shaft is being hammered through which can't be seen since there is no way to check them after the drive shaft is installed.

The drive shaft end nub should not have any play within the pilot bearing. This play will only get worse and also interfere with the operation of the clutch. Excessive play will also ruin the front drive shaft splines.

Bottom line is many want to think they can do a cheap torque tube rebuild, but in truth they are setting themselves up for a problem down the road. We know since we help many people through problems associated with such rebuilds. The torque tube should be viewed as an important part of the transaxle system and owners need to realize all torque tubes are at the age and mileage of needing a correct rebuild.

pfarah7

Der Treiber,
In fact I did use a small belt sander to shape/round the corners; there were a couple that took to the air but no eyes were poked out during the process

Der Treiber

Ok, loving the feedback so far. Yes. proceeding slowly. I've done a transmission replace, a clutch replace, and a lot of other work on my family vehicles, which, of course, take precedence, so now I am finally able to get back to the 944.

Anywhoo, Pauly and Constantine say don't use Delrin or Homo-Polymer Acetal plastics. Constantine also says don't re-use the original black inserts (mine are in really good shape). Pauly doesn't say what material he used to machine his own inserts, so what to do? Can anyone advise the best appropriate material for these inserts and/or a possible source? I guess that's a trade secret, and hence the reason to spend $250/a bearing.

I'll find a shop to machine if I can get a recommendation on the correct material.