PDA

View Full Version : broken strarter bolts



GSE2SCHMIDT
05-05-2005, 19:54
My wife calledme from arby's. Said thet at truck would not start and was just making a wierd noise. She said that it started doing it a little the day before but did not want me to worry.

So I look ounderneath and a starter bolt is missing. So looking for the quick fix I check to see if the outer bolt is tight.....I turn it and snap!

After I tow get the truck flatbedded home I look and find out the other inner bolt hole starter bold is broken up inside just like the outer. I tried to get the first/ cracked inboard bolt with a reverse drill bit.

The outboard was a different story, broke 2 taps off and finally got it ourt, but the slug must have been bent and the threads were chewed up from the removal process. So I got an helicoil(name brand) got my drillbit out and had some fun. Unfortunately the tap they give is not a bottoming tap. After much driving around and olnly able to get a bottoming tap for a 10mm 1.25 pitch not the 10mm 1.5 p pitch that the starter has. I would have gone to a 1.25 but was unable to locate a bolt longer than 75mm. I put my standard tap in my vice and smacked it with a hammer. It Luckily it broke off pretty evenly and I swas able to sand it down by hand at the kitchen table after an hour and about 10 pieces of medium grit sandpaper. I tapered the flutes of the tap so it would gradually go to full thererehredredaead after a turn and a half. I had already started my threads and marked the depth of my bit with tape so I didn't bottom out.

When I was cutting my last half thread.....damn I always have to give it that last little bit....I noticed a crack on both sides of the bolt hole urunning from the front to back. When I pulled the tap out the crack closed back up....but the damage is done.

Everything is back together for now till I find a perment true fix. What is the best way to have this fixed? Even if I take the engine out and have the block worked on I would have to to pull the internals out of the engine.....correct?

The engine has 190K If I pull it apart it will just need a rebuilt anyway, don't really want to go the replacement route eihether.

If the crakccked piecse sholuld fall off I could just PC7 or some other majic block fix stuff. I dont't think the outer bold takes as much abuse as the inner bolt so maybe the stress won't finish it off.

Anybody out there have thia problem like this?

What did you do?

What should I do?

twaddle
05-05-2005, 22:36
Hi there,
The first problem to fix, which is the cause of the broken bolts in the first place) is the support bracket at the end of the starter motor.

There should be a longer stud at the end of the starter body, a bracket should be fitted which bolts onto the engine block.
This bracket being missing or broken is usually the cause of the broken starter bolts.

Cracked bolt hole.....

I would get a good set of taps, tap out both holes as far in as you can go.
Then measure the maximum length of bolt that you can use to get as deep into the threaded hole as possible.
Get bolts that the correct length even if you have to order them in.
Be careful that the bolts don't bottom out and give you a false torque, check that the starter is solid with the bracket off first.

Use a dab of thread lock.
Install the support bracket.

With a bit of luck the bolt hole won't be cracked all the way up and with the longer bolts you can grab onto the good area.
With the support bracket installed everything should be OK.

Next, check the bracket regularly as the do fracture and break off.

I,ll check mine this morning now I think of it as I haven't for a while.

Good luck

Jim Twaddle
Biggar,
Scotland

Dvldog 8793
05-06-2005, 02:43
Howdy
Support bracket! Make sure it is tight and in place.
Starter bolts, Make sure they are TORQUED I dont remember the value(65lbs is in my head but look it up)
Crack, If you have the time get it welded. I have welded blocks in place(both Aluminum and iron) The iron in the 6.5 is pretty good stuff and welds really nice. If you wait for chunk to break out, then you will be in trouble as you'll have to build up a new boss and redrill. If you could see the crack moving under install I would bet yopu are far from breaking it out. ESPECIALLY under the load and vibration these starters live in. Find a GOOD welder that knows how to TIG weld cast and isn't affraid to do it in place. DO NOT USE any super wonder holds-everything weld-in-a-tube epoxy stuff! This stuff will get into the pores of the cast and make almost impossible to get a nice clean strong weld. It's hard enough to get all the oil out without having to worry about that other "stuff"
Hope this helps!
L8r
Conley Janssen