Can't Shift Into First

[Jim Sims]

Randy, It's hard to tell from the images but one look under the car will clear it up; if the mount flange is under the support it is installed correctly. Other than that I'm out of ideas. Jim

[Jim Sims]

Just saw the new images; the mounts are installed correctly. Jim

[TerryH]

just a casual observer here... is washer/spacer #7 on each bolt?

[john walker's workshop]

the sleeve in the mount gets pulled up to the body when the bolts are tightened. there should not be any up/down movement in the sleeve. if it's snug to the body, you should be ok.

[Jim Sims]

"The weight of the tranny is hanging from the bolt, but the big washer is still movable. I can still spin it around the bolt."

John, If the sleeve was snug I would assume the above described washer wouldn't be free to turn? Jim

[rcecale]

Jim, I thought that they were installed correctly. Like I stated, I didn't take them apart when I had the tranny out of the car, and there were no apparent problems with them prior to my taking the tranny out.

Terry, neither side has part #7 installed on it. I'm assuming that is the spring washer Jim mentioned earlier. I'll be picking up a pair of them tomorrow, but, as Jim said, I don't think they're thick enough to make that much of a difference.

Randy

[rcecale]

John, should the bolts be able to be bottomed out? They aren't just really tight, they actually get to the point whre they will not turn any more.

edit: Also, should that gap/space, as shown in the pic, be there?

Randy

[john walker's workshop]

put a washer under the bolt head. there should be one there anyways. be careful not to strip out, or damage the threads in the body. start the bolts by hand so you're sure they are going in straight. they shouldn't quite bottom out, so the washer will probably help.

[rcecale]

The bolts screwed in easily enough, so I'm pretty sure they're not stripped. I'll be picking up the washers today, on my way home from work. Gonna set a jack under the tranny and pull the whole support assy off and have a look.

I'm sure everything is gonna be installed correctly, but it won't hurt to have a closer view. I guess the big issue is whether or not that gap should be there between the metal part of the mount and the car itself. The pics I took early on in this thread don't really show that area clearly, so I don't really have a good reference.

Is it possible that the rubber in the mounts themselves became compressed over the years? It seems flexible enough, and doesn't look all cracked or anything like that. I'll have more pics this afternoon after I get it apart.

Heck, I have to pull it off anyway to route the speedo cable, and snug down the grounding strap, so it's not a complete loss.

Randy

[Beethoven]

That's the spirit, Randy!
Can't wait to hear about your first successful downshift.

[gerard vaglio]

When I installed brand new transmission mounts on my 79sc I had the same strange GAP? I thought I did something wrong but apparently not?

I've heard of people putting several washers on the bolts to take up the slack but I didn't. My transmission is hanging from the bolts and is secure but not snug up to the car??? I'm always tempted to close the gap but none of the diagrams show any additional washers so it remains a 911 riddle.

I have the same question, Is this correct???

[rcecale]

Well, I placed a jackstand under the tranny to support the weight and removed the support assembly for a look. After seeing more clearly how this thing is put together, it appears that the "gap" is not only allowable, it's expected! (Gerard, looks like you're alright!)

As John stated, as long as the sleeve that runs up the middle of the mount has contact with the vehicle and the bolt is snugged right up, everything is as it is supposed to be.




The local parts place didn't have the prescribed washer and said it would take 2 weeks for them to be delivered from Porsche, so I've opted for the next best thing...washers from Home Depot. The only question I have is, "Would it be better to use Stainless Steel or Galvanized washers?" I've got both, so I'm wide open on this one. Also, should I go ahead and use a split washer on these things, or will a flat washer suffice?

Randy

[john walker's workshop]

a 12mm split lock is factory.

[rcecale]

Well, looks like I have a problem. This is the original bolt I was replacing with a brand new one. This is exactly how it looked when it came out, except for a bit of cleaning.


While installing the replacement, the bolt will not screw all the way up into the receiver. The other side, I can turn by hand with no problems. The stripped side doesn't go much past a few turns with the new bolt.

I looked up inside and it's obvious that the threads on the car side are stripped. Is there a piece I can get to replace the stripped threads, or can I run a tap up there and re-run the thread?

Randy

[john walker's workshop]

lay the new bolt threads into the original bolt's threads and see if the pitch is the same. i would certainly try to clean up the threads in the body, because that's steel, and you will have to use a helicoil to restore them, and you don't want to get into that. be sure the thread pitch of the tap is correct. i think the pitch is 1.50, but use a thread gauge to be sure. you have one chance.

[Jim Sims]

This likely comes from a PO or previous mechanic using the screw to force the support into alignment - bad practice. If you can clean up the threads and can hold the specified torque for this screw you may be okay. Otherwise, this is an expensive repair as the female threads are in a socket welded into the body sheet metal which has to be cut out and a new one welded into place. My suggestions: Do not use a regular cutting tap. Instead get a rethreading tap of the correct size (Sears sells a nice complete set (52105) metric and US sizes for $60). Snap-On sells them too. Throughly clean out the hole with a solvent and compressed air then lube the hole and rethreading tap with motor oil and carefully start it. Make sure you are going in "squarely" and correctly threaded. Go slowly; turn 90 degrees max at a time then back up an 1/8 of a turn. You will be reforming but not cutting the threads. Periodically back all the way out and clean any debris off the rethreading tap and relube. If the tap begins to get tight, back up and clean it off and clean the hole out or take smaller "bites" (turn fewer degrees forward before backing up). Keep track of the depth for when the tap bottoms out (it will get hard to turn) you want to stop - you do not want to break off the rethreading tap in the hole. Clean out hole again with solvent and compressed air. Then plenty of anti-seize compound on the new screw and hand installation most of the way in if possible.

[rcecale]

Okay, so the car side threads are steel, what about the bolt? Is it a softer material?

Just checked online at Sears and it looks like a local store may have that tap & die set in stock. Will have to swing by there tomorrow evening.

I think I shouldn't have too much trouble picking up the thread since the stripped part is a few threads up into the socket. I'll give it a shot.

Thanks for the quick responses!!!

Randy

[Jim Sims]

The female threads are steel and usually are softer (by design) than the screw or bolt threads. Screw is at least 8.8 strength class steel and may be 12.9. The Sears set has M12 x 1.25, M12 x 1.5 and M12 x 1.75 rethreading taps so you should be able to find the correct size. Looking at the wear on my set I would second John's recollection that the screw thread is M12 x 1.5. I have done this very repair successfully with these type of rethreading taps. Go slowly and take your good sweet time; "patience" is worth $100 to $300 per hour at this point. Jim

[rcecale]

Taking my time is exactly what I'll be doing. I've come this far and I don't want to mess it up now. I'm assuming a thread gauge will be a part of the kit so I can be positive as to the thread, but I'm sure you and John know what your talking about. You guys have been right on the money from the very beginning of this thread.

Thanks again!

Randy

[Jim Sims]

There is not a thread gage in the kit but an easy way to match the correct size is to hold the tap and bolt thread against each other (side to side) so the threads interlock (hold them up to the light). If the threads match they will fit together (nest together) exactly along their entire overlapping length. Another test is to screw them both into a M12 x 1.5 nut. Cheers, Jim