I think my Cyl head is stripped where the alternator goes into it (Options?)

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will e
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I think my Cyl head is stripped where the alternator goes into it (Options?)

Post by will e »

The very long bolt that goes into the Cyl head and the alternator pivots on will not tighten down. I know it's long enough, I think the head is stripped. So what are my options? Currently it is a 6 1/2" long 7/16" course thread. Will a Heli coil work? Can I just tap it out to 1/2"?

What are your thoughts on how to deal with this?
81 Waggy 'WILL E' Retired
82 Cherokee WT - SOA/SF/high steer/Alcan springs/agr box/Borgeson steering shaft/AMC 401/performer/holley TA/HEI/BeCool/727/ALTAS (2.0/2.72/5.44)/D60 Snofighter(Yukon Zip,hubs,stubs,4.56)/14 Bolt (FF,BF shave, Discs, ARB,Artec Truss)/MTR 37X12.5/Corbeau XRS Baja & 5 point retractable harness/Hella Aux lights/tuffy console/killer32 sliders/Evil Twin bumpers, rack and roll cage/WARN 8000/TT Fabworks steering brace/dual batts/custom TC skid plate/ARB fridge

candymancan
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Re: I think my Cyl head is stripped where the alternator goes into it (Options?)

Post by candymancan »

Id try a helicoil. I mean someone did it on a spark plug on my engine so i dont see why it wouldnt work for that
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tedlovesjeeps71
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Re: I think my Cyl head is stripped where the alternator goes into it (Options?)

Post by tedlovesjeeps71 »

Pull it off and see if a similar bolt will thread without the alternator stuff. Maybe try running a tap to see if that helps. Last resort would be a helicoil like C said.
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Re: I think my Cyl head is stripped where the alternator goes into it (Options?)

Post by Stuka »

That seems like a tough bolt to strip out. Its cast iron, and its torqued that high. If the bolt won't thread without the alternator, then your only option is to helicoil if there are some threads left, or pull the head and have it fixed by a machinist.
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tedlovesjeeps71
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Re: I think my Cyl head is stripped where the alternator goes into it (Options?)

Post by tedlovesjeeps71 »

Any chance you left off a washer(s) or spacer and it was bottoming out?

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will e
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Re: I think my Cyl head is stripped where the alternator goes into it (Options?)

Post by will e »

tedlovesjeeps71 wrote:Pull it off and see if a similar bolt will thread without the alternator stuff. Maybe try running a tap to see if that helps. Last resort would be a helicoil like C said.
A couple of years ago when I changed the water pump I spent a day while all of the accessories were off and checked each hole for the thread size and depth. For the alternator bolt it was 7/16 course thread. A 1/2 inch would not fit. There is more to the story.. see below

Stuka wrote:That seems like a tough bolt to strip out. Its cast iron, and its torqued that high. If the bolt won't thread without the alternator, then your only option is to helicoil if there are some threads left, or pull the head and have it fixed by a machinist.
When I swapped the engine I had a 3/8" bolt from my 81 Wagoneer 360. This 401 came out of an early Jav. I think I messed up the threads by using the wrong bolt for a while.


tedlovesjeeps71 wrote:Any chance you left off a washer(s) or spacer and it was bottoming out?
It's not bottoming out. When I spent the day checking all of the accessory holes I confirmed the depth of each one as well. It's possible it bottomed out and then the threads stripped. Right now it 'feels' like it is just getting tight and then lets loose.




I was looking at something called a 'Time-serts' that is like a heli coil but more solid. Time-sert for this repair needs .6 inches of depth. Anyone have a head laying around they can check the depth?

Is there enough room around this accessory hole to drill it out a bit or will I get into a water or exhaust passage? For the 'time-sert' the drill is 29/64". That's just 1/64 bigger than the original bolt. But there is also some additional material removed when I tap it out.
81 Waggy 'WILL E' Retired
82 Cherokee WT - SOA/SF/high steer/Alcan springs/agr box/Borgeson steering shaft/AMC 401/performer/holley TA/HEI/BeCool/727/ALTAS (2.0/2.72/5.44)/D60 Snofighter(Yukon Zip,hubs,stubs,4.56)/14 Bolt (FF,BF shave, Discs, ARB,Artec Truss)/MTR 37X12.5/Corbeau XRS Baja & 5 point retractable harness/Hella Aux lights/tuffy console/killer32 sliders/Evil Twin bumpers, rack and roll cage/WARN 8000/TT Fabworks steering brace/dual batts/custom TC skid plate/ARB fridge

letank
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Re: I think my Cyl head is stripped where the alternator goes into it (Options?)

Post by letank »

I have used time sert to fix 2 head bolt out of 4 for one of the moto head... but it was in aluminum... easy drilling as long as you drill straight, it was a lot of metal to remove. Ran well for the last 5 seasons.
as other have said, remove and check what is the condition of the threads...

post edit for infos on timesert
Image
Last edited by letank on Tue Sep 03, 2019 9:22 am, edited 2 times in total.
Michel
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will e
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Re: I think my Cyl head is stripped where the alternator goes into it (Options?)

Post by will e »

Thanks Michel.

Can anyone confirm what the correct thread size should be?
81 Waggy 'WILL E' Retired
82 Cherokee WT - SOA/SF/high steer/Alcan springs/agr box/Borgeson steering shaft/AMC 401/performer/holley TA/HEI/BeCool/727/ALTAS (2.0/2.72/5.44)/D60 Snofighter(Yukon Zip,hubs,stubs,4.56)/14 Bolt (FF,BF shave, Discs, ARB,Artec Truss)/MTR 37X12.5/Corbeau XRS Baja & 5 point retractable harness/Hella Aux lights/tuffy console/killer32 sliders/Evil Twin bumpers, rack and roll cage/WARN 8000/TT Fabworks steering brace/dual batts/custom TC skid plate/ARB fridge
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Re: I think my Cyl head is stripped where the alternator goes into it (Options?)

Post by Cecil14 »

Can't help with the size questions, but +1 on Time-Serts over Helicoils. Possibly more expensive, but a much better product.
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Re: I think my Cyl head is stripped where the alternator goes into it (Options?)

Post by fulsizjeep »

When I rebuilt my first 401, I discovered this hole was bad from a previous helicoil repair. It was only 6 years old. I had the heads checked and valves ground and swapped sides for the head assemblies which gave me a good mounting hole. Drastic approach but I had it apart anyway.
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letank
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Re: I think my Cyl head is stripped where the alternator goes into it (Options?)

Post by letank »

if you have the AC compressor still installed you could rely on the AC holding bracketry for supplemental restrain by adding some sort of tang, or any other mounting options

Image

I updated my previous post with timesert pict it was very close in size to 29/64

what about using the upper bolt (arrow) and figuring out something for the bracket holding arm

Image
Last edited by letank on Tue Sep 03, 2019 4:53 pm, edited 1 time in total.
Michel
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derf
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Re: I think my Cyl head is stripped where the alternator goes into it (Options?)

Post by derf »

There are two bolt sizes.

The 360s I've had were one size. The 401s I've had are "one bigger". I don't recall the sizes offhand.

When I went to use the 401 with a later alternator bracket I ended up using a step bit on the bracket and it all went together fine.

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will e
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Re: I think my Cyl head is stripped where the alternator goes into it (Options?)

Post by will e »

derf wrote:There are two bolt sizes.

The 360s I've had were one size. The 401s I've had are "one bigger". I don't recall the sizes offhand.

When I went to use the 401 with a later alternator bracket I ended up using a step bit on the bracket and it all went together fine.
I think this is what got me. The smaller bolt kinda worked originally and I think it messed up the threads. Now the larger bolt won't hold.

The engine runs fine. There are several other places where the bracket mounts, so the bolt for the alternator may not really 'need' to go into the block. . Maybe one answer is to get rid of the long bolt and just mount it up against the bracket OR get a long stud and if the threads are long enough put a nut on both side of the alternator. Maybe something like this:

https://www.amazon.com/ARP-AP6-750-1LB- ... way&sr=8-2

I would have to cut threads on the alternator side thread long enough to get a nut on both sides of the alternator. Can I do this with a chromoly bolt and a tap/die set?
81 Waggy 'WILL E' Retired
82 Cherokee WT - SOA/SF/high steer/Alcan springs/agr box/Borgeson steering shaft/AMC 401/performer/holley TA/HEI/BeCool/727/ALTAS (2.0/2.72/5.44)/D60 Snofighter(Yukon Zip,hubs,stubs,4.56)/14 Bolt (FF,BF shave, Discs, ARB,Artec Truss)/MTR 37X12.5/Corbeau XRS Baja & 5 point retractable harness/Hella Aux lights/tuffy console/killer32 sliders/Evil Twin bumpers, rack and roll cage/WARN 8000/TT Fabworks steering brace/dual batts/custom TC skid plate/ARB fridge

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will e
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Re: I think my Cyl head is stripped where the alternator goes into it (Options?)

Post by will e »

Okay, an idea came to me when I woke up this morning: Drill a perpendicular hole in the alternator where the bolts goes through. Tap it and put in a 'set screw'. The screw will put pressure on the bolt and keep it from slipping out over time. I know it's cheesy. But with or without the bolt the front bracket really doesn't move, especially since I have the A/C bracket mounted too. The spacers stay tight even when the bolt works its way out. And the truck runs fine. It's an inexpensive and easy 'fix'. If it doesn't work I haven't ruined anything.

If it works, then I will feel a bit more comfortable trying to fix the thread in the head. My biggest concern is I try and fail and make the head situation worse. At which point I end up pulling the passenger side head (no fun).
81 Waggy 'WILL E' Retired
82 Cherokee WT - SOA/SF/high steer/Alcan springs/agr box/Borgeson steering shaft/AMC 401/performer/holley TA/HEI/BeCool/727/ALTAS (2.0/2.72/5.44)/D60 Snofighter(Yukon Zip,hubs,stubs,4.56)/14 Bolt (FF,BF shave, Discs, ARB,Artec Truss)/MTR 37X12.5/Corbeau XRS Baja & 5 point retractable harness/Hella Aux lights/tuffy console/killer32 sliders/Evil Twin bumpers, rack and roll cage/WARN 8000/TT Fabworks steering brace/dual batts/custom TC skid plate/ARB fridge

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Re: I think my Cyl head is stripped where the alternator goes into it (Options?)

Post by Xplitive »

The alternator top mount bolt with spacer just snapped on mine, probably due to tension from not bending the bottom bracket enough when doing the CS alternator swap.
Seem to recall lots of discussion (mostly on ifsja) about what would work and not work with the bolts and mounts. Might be worth a look and I hope you find something easy because going to have to fix mine soon too.
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Re: I think my Cyl head is stripped where the alternator goes into it (Options?)

Post by Stuka »

Just know that drilling the alternator may prevent you from using it as a core return when you need a new one. And that if one fails someplace where you don't have a drill, that could suck.

I think you ultimately need to tap the hole to be one size larger.
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will e
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Re: I think my Cyl head is stripped where the alternator goes into it (Options?)

Post by will e »

Stuka wrote:Just know that drilling the alternator may prevent you from using it as a core return when you need a new one. And that if one fails someplace where you don't have a drill, that could suck.

I think you ultimately need to tap the hole to be one size larger.

Good point on the return and if I get a new one. I've had this issue for a while. So if have to replace the alternator and not drill it for a while I think I would be okay.

Ultimately I do want to tap the hole (or do a fix like a time-sert).

I have a spare bracket too. So if that snaps or something I can swap that out pretty quick.
81 Waggy 'WILL E' Retired
82 Cherokee WT - SOA/SF/high steer/Alcan springs/agr box/Borgeson steering shaft/AMC 401/performer/holley TA/HEI/BeCool/727/ALTAS (2.0/2.72/5.44)/D60 Snofighter(Yukon Zip,hubs,stubs,4.56)/14 Bolt (FF,BF shave, Discs, ARB,Artec Truss)/MTR 37X12.5/Corbeau XRS Baja & 5 point retractable harness/Hella Aux lights/tuffy console/killer32 sliders/Evil Twin bumpers, rack and roll cage/WARN 8000/TT Fabworks steering brace/dual batts/custom TC skid plate/ARB fridge

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Re: I think my Cyl head is stripped where the alternator goes into it (Options?)

Post by Rod2 »

My gen bolt hole is 3/8 coarse I'm pretty sure because it takes a 9/16 socket and the gen ears are that size. When my threads gave out, I JB'd a short threaded rod in the hole. Then I fashioned a 3/8 threaded rod coupler to replace the original spacer, installed it about halfway onto the JB'd threaded insert tight against the head, then used a shorter, appropriate length 3/8 bolt through the alt, the rear strap, and into the coupler. It's been a coupla' years and neither head heat nor vibration has caused the JB to fail or the threads to loosen.
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