engine reinstall issue

John Brandt · 06-27-2003, 07:32 AM

We just got the motor back in the car yesterday after sitting on jackstands over the winter. (Fuel line under pres regulator was split)

engine mount bolts went in just fine

However, trhe bolts for the transmission mounts are both EXTREMLY hard to tighten. maybe on the order of 150 ft lbs just to get the thing all the way seated I'm sure they're on the threads but it appears that they're not lining up quite the way they should.

they were never this difficult on previous R&I procedures.

What happend?
what are the consequenses?

MotoSook · 06-27-2003, 07:53 AM

the trans mount bolts are easy to cross thread. that may be your case. I would back them out and chase them with the appropriote tap..go to sears and take you bolt with you..get a tap and some loctite..not sure which loctite, but someone will chime in..my sympathies..been in the same boat, but I stopped early so I didn't go as far as you have....

good luck

kstylianos · 06-27-2003, 07:59 AM

John,

I was in the same boat last night with the shock-->trailing arm bolt....would thread in ok, than get extremely hard to tighten down.

I took the bolt out, sprayed some carb cleaner in the hole and followed with a spiral brush, spray again....LOTS OF GUNK in the hole.

Bolt went back in with ease......

Jim Sims · 06-27-2003, 08:01 AM

I suggest you stop; you do not want to damage the transmission mount female threads in the body. These screws should install initially with only a small amount of torque. You must have the screws "cocked" and possibly cross-threaded. I suggest you remove the screws, chase both the female threads and the male screw threads with thread chasing taps and dies not a regular cutting taps and dies). Sears sells kits with these chasing taps and dies as does Snap-On. To ensure the screws go in easily I use a socket and extension (no ratchet or breaker bar) to start them. I also coat the screw threads with an anti-seize compound to enable easy future removal. Some may not agree with the anti-seize. Cheers, Jim

kstylianos · 06-27-2003, 08:09 AM

Jim,

I agree. If the threads are damaged, do not chase with a tap as a tap is designed to cut, not recondition. Sears does sell a thread reconditioning kit for $50 which includes the M12X1.5 tool you'll need.

John Brandt · 06-27-2003, 09:59 AM

I'm actuallly wondering if the chassis might have settled ove the winter on jackstands, causing the angle of entry of the bolt to be off a little.

i cant imagine we would have cross threaded both bolts, and they do turn probably two turns before it gets tough.

and wouldn't the bolt strip and spin with that kind of force?\

so assuming that the female part is stripped, and it surely would be given how far as I screwed it in, what next? can it be retapped with the engine still in, or am I going throught this whole thing again?

I need to go home and look at it again.

ChrisBennet · ChrisBennet's Garage

Like someone said, the transmission mounting bolt are easy to cross thread. I know of at least 3 911's with Timeserts in them for this reason.
To avoid cross threading them, loosen the 4 8mm nuts holding the support bracket to the bottom of the transmission so the bracket can move freely. This gets rid of the sideways tension on the mounting bolts and reduces the tendency to cross thread them.
-Chris

West · 06-27-2003, 10:19 AM

If it was me, I would drop the motor. Bolt the motor up to the tranny out of the car, then put it back in the car as a unit.

John Brandt · 06-27-2003, 10:19 AM

so I take it that the engine's coming back out?

Jim Sims · 06-27-2003, 10:24 AM

The female threads can be chased with the engine in place (I've done this). However, you'll likely have to make a different support arrangement at the front of the transmission as you may need to remove the support bracket (continuing on with ChrisBenet's suggestion) to gain access to the female threads with the chasing tap. Back the chasing tap out periodically and clean it of debris and then turn it in further, back out, clean and so on. Jim

West · 06-27-2003, 10:48 AM

If you remove the support bracket from under the transmission, don't let the transmission support itself by hanging on the front output shaft (gear shift shaft). That will ruin the seal around the shaft. You don't have to remove the motor to do these things, I just suggested it because to me, it always seems easier to put the motor and tranny in together bolted up.