Timing Belt tensioner mount helicoil backed out

Dennis MacGyver · **Posted:** Thu Jul 11, 2019 6:48 pm

Has anyone had this problem when changing out the timing belt tensioner ?
Came out with the bolt.
If so, what did you do, use Loctite, which type?

WWDiesel · **Posted:** Thu Jul 11, 2019 7:05 pm

I would install a new heli-coil and put some red locktite on it.
Let it dry good before screwing the bolt into the heli-coil.
Other option is to go to a Nutsert if the helicoil threads are damaged.
http://www.avdelusallc.com/products/nutsert.shtml

TKB4 · **Posted:** Thu Jul 11, 2019 7:59 pm

Yes I have had it happen on one and I know Flash has also experienced this. When I posted about this couple years ago I learned we both had the same idea to retap hole and instead of using a bolt replace it with a stud and nut setup to avoid this happening again.

TKB4 · **Posted:** Thu Jul 11, 2019 8:06 pm

Here is a link to that post
viewtopic.php?f=5&t=86675

Dennis MacGyver · **Posted:** Fri Jul 12, 2019 4:21 am

Well it looks like mine is somewhat stripped out too.
To add to a possible solution, I located these, seems like a good fit because this type of "helicoil" would have more aluminum surface to grab onto since it is a lager external diameter and still maintaining the 8x1.25 mm standard bolt requirement.
Notice it can be bought on Amazon.
The solution is not cheap, about $95, but I think it would put to bed wondering if it would ever fail again.

http://www.timesert.com/html/bigsert.html

https://www.amazon.com/dp/B003QAZUIS/re ... EWWITZXTMB

My66dodge · **Posted:** Fri Jul 12, 2019 11:46 pm

Of all the kj crd timing jobs and rocker jobs I have done I have only seen one that came from the factory with a bolt and nut, the inner timing cover has a hex punched in it and a hole through so the bolt is held and when you put the tensioner on you cinch down the nut and it can't strip. All the rest have had a hole with a threaded insert but the one was different.

TKB4 · **Posted:** Sat Jul 13, 2019 1:04 am

Thats interesting . I would like to see a pic of that if you have one. I wonder if it stripped at the factory or if it may have been manufactured at a different plant or made for a different market. Possibly a prior owner did this before brought to you?

My66dodge · **Posted:** Fri Jul 19, 2019 8:57 pm

That’s what’s weird, as a professional mechanic I can say for sure it was made that way and it doesn’t look modified... if it wasn’t such a hassle I would post a pic cause I still have the cover

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ebbnflow · **Posted:** Mon Jul 22, 2019 5:13 pm

My66dodge wrote:

Of all the kj crd timing jobs and rocker jobs I have done I have only seen one that came from the factory with a bolt and nut, the inner timing cover has a hex punched in it and a hole through so the bolt is held and when you put the tensioner on you cinch down the nut and it can't strip. All the rest have had a hole with a threaded insert but the one was different.

My 06 is like that.

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TKB4 · **Posted:** Mon Jul 22, 2019 6:16 pm

Ebbnflow
Can you check the build date and see when it was built and post it . Maybe after a particular date it was changed to being done that way. The helicoil protrudes a little maybe 1/8 th inch out toward the engine from the rear timing cover. I have two 2006 models and four 2005 models (one salvage 05) and all of them and a few more I have looked at also had the bolt . Now 3 of mine have studs and nuts.

ebbnflow · **Posted:** Mon Jul 22, 2019 9:49 pm

TKB4 wrote:

Ebbnflow
Can you check the build date and see when it was built and post it . Maybe after a particular date it was changed to being done that way. The helicoil protrudes a little maybe 1/8 th inch out toward the engine from the rear timing cover. I have two 2006 models and four 2005 models (one salvage 05) and all of them and a few more I have looked at also had the bolt . Now 3 of mine have bolts and nuts.

My build date is 5-06.

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geordi · **Posted:** Mon Jul 22, 2019 10:21 pm

I have worked on exactly two that were like that, both had the inner cover replaced with a European cover at some point in their journeys. One was done by a dealership, the other was sourced by an independent mechanic.

For fixing the helicoil, just thread the thing back in with some loctite, or if you are lucky you can match up a timesert to that hole and then it will be a solid collar.
Talk to a Fastenal shop about the timeserts, they should have them.

Dennis MacGyver · **Posted:** Tue Jul 23, 2019 12:41 am

Decided to go with the Timsert line called Big Sert 8 x 1.25,
Second repair kit for oversized holes kit # 5812. They use red LocTite on the insert installation
They sell them direct from their plant in Reno NV
So I'll end up with what looks like a threaded pipe nipple, threaded inside & out, inserted into the rear cover. I'll get it level & plumb on a drill press to make sure the hole is straight & centered in the existing spot/place.

What kind of torque is every one using on the tensioner bolt?
I see numbers of 20-29 ft lbs. which seems pretty light to me for something so important.
Does anyone use blue Loctite on the tensioner bolt itself?

TKB4 · **Posted:** Tue Jul 23, 2019 6:09 pm

I used red loctite and let it set overnight . I couldn't reuse the helicoil that came out it was uncoiled as bolt was unscrewed.

geordi · **Posted:** Thu Jul 25, 2019 2:06 am

I don't know why there would be a range for the torque. The correct number is 28 lb-ft, and that is what I have my wrench set for on every CRD timing belt tensioner I have done. Not one has had an issue.

TKB4 · **Posted:** Thu Jul 25, 2019 11:50 am

Here is where I got the idea that it was 22 ft lbs. Scroll down to tables and now obscured by photo bucket ID. Reading it now I realize I don't know the difference between timing belt tensioner bolt and timing belt retention bolt!
viewtopic.php?f=98&t=58100
This one says 22 ft lbs for timing belt tensioner.
I actually did 24 ft lbs. Now I don't know what to torque the ones with studs to but I went to 26lbs.

Here is what I used to repair the helicoil with and have several more if needed. I think it was about $14 and have not had any problems with it in about 50,000 miles on one with most miles and have had two of three apart again to replace either head gasket or rockers.

https://imgur.com/N32XnUn

https://imgur.com/mSPaqDZ

From now on probably will use 28 ft lbs.

WWDiesel · **Posted:** Thu Jul 25, 2019 3:11 pm

according to the FSM:> http://www.colorado4wheel.com/manuals/J ... Manual.pdf
As usual, the FSM shows different values depending on where you look in the manual.
Clear as mud! :banghead:

these are the referenced torque values that can be found in the 05 FSM.
NOTE: Both the 05 & the 06 FSM list the same torque values.

Section 9 - Page 250 2.8L COMMON RAIL DIESEL ENGINE KJ
TIMING BELT IDLER PULLEY
Install timing belt idler pulleys. Torque bolts to 47.1N·m. (Fig. 165). 47.1Nm= 34.73918ft-lb

Section 9 - Page 255 2.8L COMMON RAIL DIESEL ENGINE 9 - 255
TIMING BELT/CHAIN TENSIONER & PULLEY ADJUSTMENTS
ADJUSTMENT - TIMING BELT TENSIONER
(3) Align timing belt tensioner using special tool 9660, with the alignment pointer as shown and torque timing belt tensioner retaining bolt to 34.7N·m. = 26 ft. lbs. (Fig. 176)
(4) Rotate engine 2 complete revolution and then recheck tensioner alignment. Readjust tensioner alignment as necessary.

Section 9 - page 186 2.8L DIESEL TORQUE SPECIFICATIONS:
Timing Belt Idler Pulley Bolt 47.1 35 N m
Timing Belt Tensioner Bolt 29.4 22 N m

But I do tend to agree 28 ft. lbs. is probably not going to hurt anything as it is only 2 ft. lbs over the rated torque, unless the helicoil is already in a weakened state.

WolverineFW · **Posted:** Fri Jul 26, 2019 1:27 am

Good choice.

That is also the recommended repair item for fixing the notorious Ford Triton V8 heads when they eject their spark plugs and trash the threads.

Dennis MacGyver wrote:

Decided to go with the Timsert line called Big Sert 8 x 1.25,
Second repair kit for oversized holes kit # 5812. They use red LocTite on the insert installation
They sell them direct from their plant in Reno NV
So I'll end up with what looks like a threaded pipe nipple, threaded inside & out, inserted into the rear cover. I'll get it level & plumb on a drill press to make sure the hole is straight & centered in the existing spot/place.

What kind of torque is every one using on the tensioner bolt?
I see numbers of 20-29 ft lbs. which seems pretty light to me for something so important.
Does anyone use blue Loctite on the tensioner bolt itself?

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TKB4 · **Posted:** Fri Jul 26, 2019 9:59 am

Section 9 - page 186 2.8L DIESEL TORQUE SPECIFICATIONS:
Timing Belt Idler Pulley Bolt 47.1 35 N m
Timing Belt Tensioner Bolt 29.4 22 N m

to clarify the first numbers are Nm the second ones are foot lbs so

Timing Belt Tensioner Bolt 29.4 Nm or 22 ft. lbs.

I know when turning the TB by hand to check timing etc on replacement the tensioner will often not maintain belt tension even after belt stretched some and readjusted so I think to err on little more torque is safest bet.

Timing Belt tensioner mount helicoil backed out

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