Timesert splitting in half? Need Help
 

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. :mad::mad:

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!!!!

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

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?

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

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?

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.

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.

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

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

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

Sorry, just trying to humor myself with this issue. :)

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?

http://forums.pelicanparts.com/uploa...1415411594.jpg

Oops here you go.http://forums.pelicanparts.com/uploa...1415412111.jpg

Last pic. timesert top-half:

http://forums.pelicanparts.com/uploa...1415412252.jpg

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

Yup, basically that's it.

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

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!

Transmission mount bolt length........
 

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

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.

Transmission mount bolt length.......
 

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

When I did mine I use Big-Sert kit # 5215 also made by Time-Sert.

As the name imply, it heavy duty.

http://www.amazon.com/gp/product/B003QB5I52/ref=oh_aui_detailpage_o08_s00?ie=UTF8&psc=1

I made this myself, but if you want stock thread size, it's M12x1.5:

Kit Nr. 5215

Roland,

Absolutely correct. I check my order and it was the M12x1.5 kit.

Glad you have the correct size then. :)

From what I understand, bigserts are to fix incorrectly done timesert jobs.

A little confused: what is this kit and whet did you make?

Thx.

I made this because there was a not rectangular time sert, but I did not knew until changing from rubber to solid mounts. Here you find some details:

++ BIG-SERT Oversized thread repair kits ++ thread repair kits for oversized holes, previously repaired threads oversized holes

of course no need if you only have a damaged stock thread. then a normal time sert is enough, or a helicoil too, depending on what you prefer. But if like my case, the only solution is a big sert

:). I am still thick headed. I know about Big Sert which is used to fix botched up tapping job.

But are you saying You made the kit (i.e., you invented it?). If you did, glad to have an inventor as part of the Pelican family. :)

oh no! I did not made the kit, I bought it and made the job. Sorry for my poor language skills here:(

:). Perhaps it was my poor comprehension. :)


Anyways, so far my analysis regarding needing longer bolts is correct. I could not find 65 mm bolts today but I did find a 70mm.
I am also waiting for longer insert.

I will redrill and retap again hoping that this 4th timesert job will not result to having to do a BigSert job. :)

These kits cost!!!!!!!

Perhaps if I end up needing a BigSert job, someone can rent me their BigSert kit. :)

How thick are the washers?
 

cab83,

I did some calculations using your M12 x 1.5 x 60 mm.

OEM transmission mount thickness approx............................. 39 mm
Protruding length of bolt.............................................. ........ 6 mm
Remaining length used by washers........................................ 15 mm (?)

Total............................................. ................................. 60 mm

What thickness (mm) are your washers?
Could you measure the thickness (mm) of the transmission mounts?

Thanks, Tony

The washer for the bolt is 2mm. Don't forget that the big washer, the one that covers the rubber housing (60mm), is also about 2 mm.

The xmission mount is about 39mm.

Lastly, I believe that the last 8mm from the tip of the cone is actually useless. :(

If my bolts are actually too short, I wonder how many of us are out there with these short bolts.

I am not an engineer, but I would think that since these bolts are barely inside the female thread, perhaps all the shaking, stress and pressure of the engine/tranny weight result to damaged threads---and perhaps, if this theory is true, we should stop blaming our mechanics. :). Jk!

In cases like this, my goal is to get a length of 1.5 times x diameter, more does not add any strength. Here it's 18mm then

Rent my kit is possible, but the fact I am in Switzerland does not make this realistic regarding the shipping costs...

Well, I believe that my big-sert job was a perfect fit. Very tight.

Just fyi, the drill for the big-sert is a lot longer than the time-sert. This means that your car really needs to be way way up higher to have leverage.

I also use the tap die guide as a drill guide just to ensure I am plumb and straight. I used aluminum foil to enlarge the diameter.

The tap guide is highly recommended for this job (for both timesert and big sert).

I also fabricated tranny mounting bolts since the factory ones that I have were "too short." With the fabricated bolts, I definitely know that I have 16mm worth of threads holding the tranny. :)

http://forums.pelicanparts.com/uploa...1419748713.jpg

http://forums.pelicanparts.com/uploa...1419748807.jpg

Use a helicoil kit like they use on aircraft engines. Timeserts are weird! No-one uses them in the UK.

Interesting. From what I have read, time-Serts are a lot better. Perhaps I should re-read and update myself.

I'll wait for others to chime in also.