OK 6.2 Guru's, starter bolts again!!!

[george carousos]

Hello All,

My 1985 Blazer breaks the outer starter bolt about every 6 months. The front brace is on and checked to make sure its secure. I can't figure out why the starter bolts keep breaking. Doesn't matter if its GM or parts store replacement like Kragens, the outer unit snaps off and leaves the wife stranded. The truck is used mainly around town, never hauling heavy stuff and only stays on pavement. No rough roads, etc. Mainly a mommy mobile. I've searched the forum and reviewed the 1998 Removal and Replacement guide but nothing that were doing seems to be the culprit. Any ideas or fixes would be appreciated.
Thanks,
George

[Dvldog 8793]

Howdy
When I was in The Marines we had such a chronic starter-bolt problem that I illegally bought 6 bolts on my own to keep my trucks running. It would normally take Uncle Sam about 2-3 weeks to get me bolts! Anyways, the only fix that I found was to make sure that they were shimmed out properly. I never found this to be an exact science, mostly I did the trial and error thing. I think what happens is that if not shimmed out right then the starter hits too hard and torques your bolts to what the point of breaking. Of coarse I maybe wrong in this but it was the only thing that I found to work marginally well for the 76 hummers and cucvs that I was in charge of.
Most of the cucvs were early 80s late 70s so they would be the same vintage as your truck.
Hope this helps!
L8r

[george carousos]

Thanks,

I'll talk to the mechanic about the shimming. I can't imagine an easier life for my wifes truck other than it gets started 6-8 times a day. Sounds pretty normal on starter engagement too.

I thought I maybe got defective bolts. Oh well.

George

[britannic]

1985.5 up are supposed to not use shims, but before they were.

I check the clearance in any case: .20-.80" in the gap between a starter gear tooth and two of the ring gear's teeth. Anything outside of that, will require shimming one or both sides of the starter to block interface.

[CleviteKid]

Amen to checking the clearance, and adding shims if required so the gears don't bind.

Also, the combination of steel bolts and aluminum starter housing can allow the preload to relax on the starter bolts. Loose bolts will fatigue and break. Next time you put in new bolts smile.gif and torque them to 40 ft-lbs, come back in a week and check the torque, and check it again in two weeks, then once a month for 3 or 4 months, or until the bolts stop moving when you re-torques them.

I still put the torque wrench on at every oil change to be sure nothing is geting sloppy.

Dr. Lee :cool:

[george carousos]

Thanks Dr Lee and others,

I'm doing the project tonite so I'll check everything and keep an eye on the re-torque situation.

Thanks again,
George

[TonyL]

I used BLUE locktite on mine and havent had a problem with the bolts loosening in the year and half since I put the starter in. Also my truck had the branket in the front but the holes were badly worn and elongated so it did't support the starter very well, might be something else to check.

Tony

[CleviteKid]

Loctite will definitely keep the bolts from TURNING, but the softer aluminum starter housing can still compress and relax the tension preload on the bolts. I still recommend that the actual 40 ft-lb torque be checked with a torque wrench at every oil change.

Dr. Lee :cool:

[Dvldog 8793]

.......Don't forget to adjust your torque for the lubricity of locktite or any other such stuff that you put on the threads. Also if you locktite them, retorque is questionable. I would have to agree with Dr.Lee that there really is no substitute for a torque wrench.
L8r
Conley

[CleviteKid]

I am on board with Conley - the torque wrench is the key.

Any of you use lock washers, . . . or LocTite, . . . or cotter pins . . . on your lug nuts? ;) The only thing that keeps the wheels on your truck (and thus keeps the shiny side up and the dirty side down) is the correct torque value.

Dr. Lee :cool:

[george carousos]

My big fear of loctite is if the future bolt does break off again, trying to get it out after being loctited might be a real pain. I think that the "blue" stuff is pretty mild compared to the "red" stuff. I'm going the retorque method on this go around and see how long they last this time.

Thanks,
George

[84 Convert]

PLEEEEEEZE! No loctite! I once broke a starter bolt in the middle of nowhere and the fact that it wasn't loctited saved my bacon. Blue is definitely better in this case than red, but say yes to the torque wrench. At work we once spent 17 man-hours removing 10 10mm bolts that had red loctite on them!!

Gregg

[Larry Andrews]

One thing that I can add. It's probably not a good idea, but it's worked for me for a LONG time now.

Once the threads in the block strip out (common) a lot of people will put in M10 helicoils. When I bought my van, one of the bolts was missing and sure enough, there was an M10 helicoil in there, very poorly installed. Once I removed the old, stripped helicoil, it was pretty obvious that this thing had been monkeyed with pretty badly. It looked like a blind dentist had been in there!

After trying all sorts of things to force the M10 helicoil to work, I finally just broke down and carefully re-drilled the holes and put M12 helicoils in the block with red loctite followed by an I.D. wipe with an isopropyl drenched q-tip. Then I drilled out the bolt holes in the starter and put everything back together with grade 8.8 bolts. Went to the dealer and paid the $4.75 for the bracket to hold the back of the starter on there and haven't had a problem since.

[TonyL]

To remove a bolt with red loctite all you need is a little heat. With blue you shouldn't have a problem. I also toqued mine and checked them , but the loctite is a little extra insurance in my mind.

Tony