Stripped thread in carrier for caliper bolt - time sert?

[reds12]

Hello - first time poster and frequent lurker here!

This forum has been extremely useful for info and I was hoping I could pick your brains on an issue I have encountered on my '98 996 C2.

Quick weekend job (famous last words) of replacing disks/pad/shoes was going smoothly until fastening the last caliper bolt - OSR (with new T55 bolts) and yep, it just keeps spinning. Back it out and I can see the thread is almost non-existent.

Now my dilemma - I've already replaced all the suspension/arms etc. a few month ago and the thought of removing the carrier fills me with utter despair. There's a decent engineering shop c15 mils away but naturally won't work on the car in situ (and I'm not driving it with only one bolt in!).

I note a few threads on here already and this appears to be a fairly common issue. A chap posted his solution of using a time sert with a jig that he had made, and whilst I'm fairly handy with tools I have no access to any machining equipment and can't even find a kit online to consider this (Wurth only seem to sell to trade?).

I ran this past my specialist and the solution was as above, time sert in situ or remove hub and get it fixed by an engineering shop.

Does anyone have any practical advice please? Where to buy a kit, or whether anyone makes a jig for the job? Or should I just suck it up and take the carrier off? Many beer tokens could be exchanged for anyone local to me (Taunton) who would be willing to help!

I was trying to get the car ready for Simply Porsche next weekend but it's not looking great at the moment...!

Many thanks for your time in reading this - any advice/guidance welcomed.

 

[infrasilver]

I've never had to do it myself but I have heard of people making their own jig and renting a 90 degree drill as you would struggle to get a normal drill in the space available. It should drill out easily with it being aluminium and there are various kits out there for the timeserts.

 

[Kat1]

I had what I believe was a similar problem with a mate's Boxster.

Multiple track days since all appears OK.

Did a bit of a write up : http://911uk.com/viewtopic.php?t=123919&highlight=

I have never heard the expression "time sert' which appears to be a Wurth product for the trade.

Helicoil is the phrase used in my world for what appears is a similar product which in my opinion more readily available.

Good luck.

 

[reds12]

Many thanks both for your input and that write up is helpful too.

From my initial research it appeared time serts were a stronger option as opposed to helicoil - being a thicker threaded insert etc.

Helicoil does appear to be a more straight forward/easier to access solution and my concern of it not being strong enough for a brake caliper has been appeased somewhat by others taking this route!

The RS Comps kit looks like it'll be good...now to worry about a drill and jig...

Thank you again, I'll report back when I make some progress!
Will

 

[berni29]

Hi

I think if you drive carefully with the faulty bolt in its hole then you should be OK. Thats if the engineering Co will do it in situ. If you DIY it (I would) then I hope it all goes well!

Berni

 

[infrasilver]

Hi

I think if you drive carefully with the faulty bolt in its hole then you should be OK. Thats if the engineering Co will do it in situ. If you DIY it (I would) then I hope it all goes well!

Berni

To add to this, you could also put a longer, thinner bolt through the stripped hole and put a lock nut on the end, that will be a lot more secure than a single bolt as you never know when you need to do an emergency stop.

 

[deMort]

Time serts are what we use in the trade .. an example ..

https://www.ebay.co.uk/p/10025144522?iid=233509866319&chn=ps&norover

As you can see they are expensive ( not necessarily the size for your car ) , you will also need a 90.degree drill .

There are ways to clamp a caliper on one side so it can be driven but i'm not going to advise you do that .

Helicoil is the cheaper alternative , having used both i know what i prefer though .

Hub removal and a garage doing this is your only option other than a helicoil though .

 

[kurlykris]

Wow that Wurth Timesert kit looks expensive for what it is, a £5 drill bit, a £5 counterbore bit, a £5 tap and a £5 insertion tool + 5 Timeserts at about £30 each :nooo: :floor:

I`d buy the tools seperately and just buy the Timesert that you need and save yourself £140 :grin:

Helicoil would do the job, but the Timesert is a better solution and stronger :thumb:

 

[reds12]

Many thanks all for your responses.

I'm leaning toward the helicoil (or I was until I caught up with this thread!). I can see the advantage of the time sert but like you say it is a branded kit so you pay through the nose as Joe Public - more to the point, I'm struggling to find individual pieces. M12 1.5 doesn't seem to be that widely used and I could do without the bother of procuring from the states.

I will order the RS helicoil kit this morning, the drill shouldn't be much of an issue - any sign of problems however and then the hub will be coming off!

Much appreciated being able to discuss here, I'm more than happy working on the car but I like to at least try and be informed of what I'm getting into! I'm confident enough with this and shall let you know how I get on!

Thanks again, Will

 

[IanG1]

When I had similar woes I ended up changing out the rear hub in the end, picked one up from a breakers and swapped out the bearing as a precaution. I made the mistake of trying to use an easy out on the snapped bolt which you guessed it also snapped. No way was it then drilling out. Local machine shop wanted the hub off to anyway if they were attempt to repair so SH hub was cheapest option.

 

[reds12]

When I had similar woes I ended up changing out the rear hub in the end, picked one up from a breakers and swapped out the bearing as a precaution. I made the mistake of trying to use an easy out on the snapped bolt which you guessed it also snapped. No way was it then drilling out. Local machine shop wanted the hub off to anyway if they were attempt to repair so SH hub was cheapest option.

Thanks for that, fortunately mine is stripped rather than having anything snapped in there. That was the other consideration though - my bearings are fine at the moment so suspect taking one hub off will mean I'll be looking at replacing bearings both sides, and knowing my luck, driveshafts too!

I'll make a contingency fund for addressing hubs/bearings/machine shop costs in the future!!

 

[Paul_S]

I did exactly that on my 996 a few years ago, last caliper bolt just spinning and on removal all of the thread from the hole came out with it.

I called my local specialist, advice was it's ok to drive with 1 bolt properly torqued up but obviously don't go nuts with the braking.

I was told it was a common issue, fix was under £100 and involved a time-seit as described by the other guys on here.

 

[pooga]

Had exactly the same problem back in March when I replaced my brake disc.

I ended up calling out Dave from The Thread Wizard - he based in New Forest and came out to me in Yateley near Farnborough. He used time sert, all done while on the car, I just had to remove the disc.

 

[Uber996au]

Had exactly the same problem back in March when I replaced my brake disc.

I ended up calling out Dave from The Thread Wizard - he based in New Forest and came out to me in Yateley near Farnborough. He used time sert, all done while on the car, I just had to remove the disc.

As a machinist in my earlier career, and a lifetime car/bike tinkerer, I would strongly advocate this type of approach for anyone who is not at least a very proficient hobbyist in metalworking. An in-situ repair like this is not the time to learn how to tap your first hole. I have had to try to recover numerous botched thread repairs / broken bolt extractions which made a fairly easy job into an extremely difficult one or indeed ruined the part. If there's a thread repair guy operating in your area, I'd suggest it's money well spent.

 

[reds12]

I called my local specialist, advice was it's ok to drive with 1 bolt properly torqued up but obviously don't go nuts with the braking.

I was severely tempted but specialist is a bit too far (c35miles) and over the hills which is more what was making me nervous about doing so...!


Thank you Pooga, that's the exact type of thing I hoped to hear! I will investigate that further. It's been such a long time since I've needed any proper garage type work (excluding specialist) and I'm sure they've all shut down, that or it's just main dealers! I'd rather break the car than someone else...pigheaded I know!

Uber, I do sympathise on that and for that reason I've reached out to a friend with an engineering background who has done this plenty of times before and is going to be kind enough to assist me with it ie he can drill it! I've also been lectured on time sert vs helicoil in depth now - whilst annoying this has happened at least I'm learning something in the process!

Any one in my area who has a time sert kit and fancies some beer then please drop me a line....

Thanks once again all, appreciate the input