Timesert splitting in half? Need Help

cab83_750 · 11-05-2014, 06:17 PM

So, it looks like my Timesert repair from 3 years ago did not last: When I removed the tranny bolt a few weeks back, I noticed that half of the timesert stayed with the bolt and half stayed in the tapped hole. So I said, "NO BIGGY!"

So last night, I redrilled, retapped and used the extra 15mm insert that came with the kit. I even used JB weld to lock the timesert and eliminate the slight looseness (or to lock it in). Tonight, I tried to install the tranny, and amazingly, the timesert split in half AGAIN without even hitting the 58 ft/lb.

What am I doing wrong? Has anyone screwed up a repair? If so, what was the repair to the repair?

I am about to drill though that hole and just put a "bolt and nut" as a replacement --- only if I could.

I should probably wait for daylight so I could really analyze where I stand with the inserts, the hole, the bolt, etc. I guess I am entitled to make a mistake............Help!!!!

tctnd · 11-05-2014, 07:14 PM

Are you certain that the insert and bolt are both correct? If you mix up metric and imperial hardware (or even some alternate metric standards like JIS) bad things can happen.
regards,
Phil

cab83_750 · 08:30 PM

You have a valid question.

So, here is just what I did:
1. Verified the kit: Part #1215 M12 x 1.5
2. I took my caliper and measured the bolt and the insertion tool. Same = 11.5mm
3. Mated the bolt- and insertion tool and the threads mated/lined up perfectly. 1.5 mm between threads.
3. Insertion tool threads perfectly into the insert.

Did you guys use the carbon steel or the stainless steel insert?

Porboynz · Porboynz's Garage

Make sure the bolt is not bottoming out because of missing washers or wrong bolt, that will destroy a thread real quick.

john walker's workshop · 11-06-2014, 04:10 AM

timeserts are too soft for that job.

cab83_750 · 11-06-2014, 05:53 AM

Quote:

Originally Posted by john walker's workshop

timeserts are too soft for that job.

Wow! I suspected that much; thus, my stainless steel inquiry. Do you recommend a 'harder' or different kit taking into account that I have already used the timesert kit?

cab83_750 · 11-06-2014, 06:05 AM

Quote:

Make sure the bolt is not bottoming out because of missing washers or wrong bolt, that will destroy a thread real quick.

Right bolt, wAsher installed. Actually I think I may need a somewhat longer bolt since my preliminary inspection tells me that the bolt is just biting the first 6-7mm of the insert.

cab83_750 · 11-06-2014, 10:53 PM

I can't wait for Saturday to get this fix.

Out of curiosity, on an '83SC, does anyone know what would happen if I drilled through the hole and mount a bolt-and-nut? From what I recall, the end of the banana arm might be in the way so they may not be room for the nut.

From what I also recall, the older 911's do have a nut and a bolt that secures the transmission; thus, I am inquiring if drilling thru and using a nut and bolt would fix this issue once and for all for everyone.

Thanks.

Tom F2 · 11-07-2014, 02:20 AM

Quote:

Originally Posted by john walker's workshop

timeserts are too soft for that job.

So, what is the correct way to repair the thread?

LJ851 · 11-07-2014, 07:02 AM

Quote:

Originally Posted by cab83_750

Right bolt, wAsher installed. Actually I think I may need a somewhat longer bolt since my preliminary inspection tells me that the bolt is just biting the first 6-7mm of the insert.

There are no threads capable of supporting the full torque load of a bolt @ 50% engagement. Obviously the timesert was the weakest link.

cab83_750 · 11-07-2014, 04:36 PM

Ah yes... That's what Capt Obvious (me) posted before. Jk!

Sorry, just trying to humor myself with this issue.

Quote:

Quote de cab83_750

Right bolt, wAsher installed. Actually I think I may need a somewhat longer bolt since my preliminary inspection tells me that the bolt is just biting the first 6-7mm of the insert.

There are no threads capable of supporting the full torque load of a bolt @ 50% engagement. Obviously the timesert was the weakest link.

cab83_750 · 05:30 PM

Still waiting for some ideas from everyone. Anyways, here are some pics that justify that our cars (or perhaps just mine) actually need longer bolts. This probably explains why the holes are so easily cross-threaded (basically, the bolts just thread in around <40%). So, this means that the first 6mm of the threads are the critical ones. Anything beyond that is worthless ---without having to buy a longer bolt !!!

While i am waiting for other input, my plan now is to redrill and retap. I would also need to purchase longer insert and longer m12x1.5 x 65 (or 70) bolt. I really don't want to resort to having to buy a bigsert so I will try this path.

Anyone has access to "Belzona!" I am willing to pay (instead of your stock just wasting away.

Or, does anyone know where to get Belzona in small quantity?

cab83_750 · 11-07-2014, 05:02 PM

Oops here you go.

cab83_750 · 11-07-2014, 05:04 PM

Last pic. timesert top-half:

Jcslocum · 11-08-2014, 03:35 AM

A longer bolt with no point on the end to get more engagement. That is where I would go.

cab83_750 · 11-08-2014, 06:50 AM

Yup, basically that's it.

That pointed design may have helped assembly when new at the factory but a bad design afterwards - IMO.

Quote:

A longer bolt with no point on the end to get more engagement. That is where I would go.

uwanna · 11-08-2014, 08:59 AM

Quote:

Originally Posted by Jcslocum

A longer bolt with no point on the end to get more engagement. That is where I would go.

Not too long,or it will "bottom out". As far as the pointed bolt, that is done to help align
the bolt with the threads and prevent cross threading. You will find many threads on this forum with woeful tales of cross threaded bolts and ruined threads, even with the point to guide the bolt! If the bolt had just a squared off end you would have seem many many more!
The main lesson for engine/trans reinstall is loosen the four nuts on the bottom of the 915 mount, giving you wiggle room to line up the holes. Then insert the bolts and thread them in finger tight to make sure they are not cross threaded. Next use a socket to slowly tighten, but back off if it feels like it's binding!

boyt911sc · boyt911sc's Garage

Quote:

Originally Posted by cab83_750

Right bolt, wAsher installed. Actually I think I may need a somewhat longer bolt since my preliminary inspection tells me that the bolt is just biting the first 6-7mm of the insert.

cab83,

What's the total length of your transmission mount bolts? I have a new one that measures about 65 mm long (including the coned end) and threaded at 59 mm. When I place all the washers and the bolt through the transmission mount, there is about an inch protruding. Approx. 25 mm compared to your 6 mm length. Keep us posted.

Tony

cab83_750 · 11-08-2014, 01:40 PM

Tony,

Your 65mm measurement excludes the head, correct? Mine is just 60mm to the tip of the cone. Where did you get yours? Mine are from Pelican. Is it possible that there are 2 sizes and mine are the shorter version?

Thanks.

boyt911sc · boyt911sc's Garage

Quote:

Originally Posted by cab83_750

Tony,

Your 65mm measurement excludes the head, correct? Mine is just 60mm to the tip of the cone. Where did you get yours? Mine are from Pelican. Is it possible that there are 2 sizes and mine are the shorter version?

Thanks.

cab83,

Not sure if there is a difference in length but the one from Pelican Parts is (930-375-317-01) and the one I have is 930-375-531-00 at 65 mm length (excluding the hex). It was bought from a Porsche dealer. Plus you could not perform an engine partial drop if you only have about 6 mm available length (?). All the coned transmission bolts that I have seen and worked with have about 1" length protruding out from the transmission mount not 6 mm.

I remember doing a partial drop by loosening the two (2) transmission bolts and created an additional space between 1/2" to 3/4". And transmission bolts were still threaded to the body. You definitely need the correct length bolts.

Tony