Re: Trans pan bolts mess
[Re: cudaman1969]
#3086733
10/17/22 07:39 AM
10/17/22 07:39 AM
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Joined: Jan 2006
Posts: 8,162 USA
360view
Moparts resident spammer
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Moparts resident spammer
Joined: Jan 2006
Posts: 8,162
USA
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A small rant here, 2005 Dakota 3.7 4x4 auto trans. Seems the powers got it wrong, they changed the tried and true 5/16 course thread bolt that we’ve used quite well for 60+ years to a M8-1.25 mm FINE THREAD bolt. Out of the 13 I just did 9 helicoils because when removing they pulled the treads out with them. Fine tread and aluminum don’t mix to well. One hour Filter and fluid change took two days. Has anyone else have this problem? Not sure what trans it is, does not look like the 904-727. 180,000 miles and still looks good though. Of course that V6 is a weak puppy. Rant over. I posted here of going through the same problem with the trans pan on a 2005 3.3L I blamed it on the dealership mechanic using a Torque gun to put the pan back on. Your info now has me considering whether it happened taking the pan off. Did the metric change happen between 2004/2005 model years?
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Re: Trans pan bolts mess
[Re: 360view]
#3086773
10/17/22 10:17 AM
10/17/22 10:17 AM
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Joined: Jan 2004
Posts: 8,193 fredericksburg,va
cudaman1969
OP
master
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OP
master
Joined: Jan 2004
Posts: 8,193
fredericksburg,va
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A small rant here, 2005 Dakota 3.7 4x4 auto trans. Seems the powers got it wrong, they changed the tried and true 5/16 course thread bolt that we’ve used quite well for 60+ years to a M8-1.25 mm FINE THREAD bolt. Out of the 13 I just did 9 helicoils because when removing they pulled the treads out with them. Fine tread and aluminum don’t mix to well. One hour Filter and fluid change took two days. Has anyone else have this problem? Not sure what trans it is, does not look like the 904-727. 180,000 miles and still looks good though. Of course that V6 is a weak puppy. Rant over. I posted here of going through the same problem with the trans pan on a 2005 3.3L I blamed it on the dealership mechanic using a Torque gun to put the pan back on. Your info now has me considering whether it happened taking the pan off. Did the metric change happen between 2004/2005 model years? No clue when but I say the first year of that trans. Just a poor design imo. BTW bolt came out with the trans threads still in the threads of the bolt. The previous time I had the pan off (70,000 miles) I tightened them with a 4–1/2” long 1/4” drive ratchet (using my fingers not the palm) no way where they overtightened.
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Re: Trans pan bolts mess
[Re: moparx]
#3086844
10/17/22 12:42 PM
10/17/22 12:42 PM
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Joined: Jan 2004
Posts: 8,193 fredericksburg,va
cudaman1969
OP
master
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OP
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Joined: Jan 2004
Posts: 8,193
fredericksburg,va
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too bad you had to helicoil those holes. they should have been a course thread to start with. if that had happened to me, i would have either helicoiled to a course thread on all the holes, or just drilled and tapped the case to either 5/16-18 or 3/8-16 thread. provided there was enough meat around the thread bosses. I thought of that too but the helicoil are stainless so I doubt they will strip out now
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Re: Trans pan bolts mess
[Re: moparx]
#3087101
10/18/22 10:15 AM
10/18/22 10:15 AM
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Joined: Jan 2003
Posts: 74,907 U.S.S.A.
JohnRR
I Win
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I Win
Joined: Jan 2003
Posts: 74,907
U.S.S.A.
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too bad you had to helicoil those holes. they should have been a course thread to start with. if that had happened to me, i would have either helicoiled to a course thread on all the holes, or just drilled and tapped the case to either 5/16-18 or 3/8-16 thread. provided there was enough meat around the thread bosses. I looked at the specs because I thought the same thing about changing them to 5/16-18 but the drill bit for a 5/16-18 is smaller than the required 8mm hole. Might be better to helicoil them to 5/16-18 ? I've done that on a trans I know would have the pan on and off a lot.
running up my post count some more .
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Re: Trans pan bolts mess
[Re: JohnRR]
#3087226
10/18/22 04:54 PM
10/18/22 04:54 PM
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Joined: Sep 2003
Posts: 19,239 north of coder
moparx
"Butt Crack Bob"
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"Butt Crack Bob"
Joined: Sep 2003
Posts: 19,239
north of coder
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too bad you had to helicoil those holes. they should have been a course thread to start with. if that had happened to me, i would have either helicoiled to a course thread on all the holes, or just drilled and tapped the case to either 5/16-18 or 3/8-16 thread. provided there was enough meat around the thread bosses. I looked at the specs because I thought the same thing about changing them to 5/16-18 but the drill bit for a 5/16-18 is smaller than the required 8mm hole. Might be better to helicoil them to 5/16-18 ? I've done that on a trans I know would have the pan on and off a lot. 5/16-18 tap drill size is "F" drill [.257] M8x1.25 tap drill size is "H" drill [.266] 3/8-16 tap drill size is 5/16 [.312] the required hole size for a 5/16-18 helicoil tap is "Q" drill [.332] the required hole size for a M8x1.25 helicoil is 21/64 drill [.328] lots of possibilities here. just be sure there is enough meat around the hole so the case won't be weakened by drilling the tap drill size required for the hole repair.
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Re: Trans pan bolts mess
[Re: jpm1916]
#3087538
10/19/22 05:04 PM
10/19/22 05:04 PM
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Joined: Jan 2006
Posts: 8,162 USA
360view
Moparts resident spammer
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Moparts resident spammer
Joined: Jan 2006
Posts: 8,162
USA
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Heilcoil what you need then put in all studs and nuts I like that suggestion
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Re: Trans pan bolts mess
[Re: moparx]
#3087682
10/20/22 06:11 AM
10/20/22 06:11 AM
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Joined: Jan 2003
Posts: 21,474 N.E. OHIO, USA
A12
Too Many Posts
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Too Many Posts
Joined: Jan 2003
Posts: 21,474
N.E. OHIO, USA
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too bad you had to helicoil those holes. they should have been a course thread to start with. if that had happened to me, i would have either helicoiled to a course thread on all the holes, or just drilled and tapped the case to either 5/16-18 or 3/8-16 thread. provided there was enough meat around the thread bosses. I looked at the specs because I thought the same thing about changing them to 5/16-18 but the drill bit for a 5/16-18 is smaller than the required 8mm hole. Might be better to helicoil them to 5/16-18 ? I've done that on a trans I know would have the pan on and off a lot. 5/16-18 tap drill size is "F" drill [.257] M8x1.25 tap drill size is "H" drill [.266] 3/8-16 tap drill size is 5/16 [.312] the required hole size for a 5/16-18 helicoil tap is "Q" drill [.332] the required hole size for a M8x1.25 helicoil is 21/64 drill [.328] lots of possibilities here. just be sure there is enough meat around the hole so the case won't be weakened by drilling the tap drill size required for the hole repair. moparx from your tap drill sizes it would appear the 8X1.25 mm bolt is nearly equal to the 5/16-18 if not slightly LARGER by 0.009". Not much but nearly equal but still larger. Also in metric fasteners an 8X1.25 is not considered a fine thread, a fine thread 8mm bolt would be an 8X1.0 or 8X.08. That being said an 8X1.25 has 20.32 threads per inch compared to (5/16)-16 per inch so not that big of a difference in engineering standards for fasteners. A 5/16 bolt is 7.9375 mm which again is shorter than an 8mm bolt and would be threaded in a minimum of 0.0535" more than a 5/16. Meaning the 8X1.25 is actually stronger than a comparable 5/16-18 bolt or fastener and the claim of putting weaker fasteners would not hold (pun) up in engineering court The case of the of I didn't use a torque wrench and who the #3LL ever does when putting pan bolts on so chalk it up to "damn I hate when that happens and now I have to Helicoil them". The only way that an 8X1.25 mm bolt could pull the threads of an aluminum case/trans housing would be if there was LESS than 8mm worth of bolt threaded into the aluminum and that's not including the pan and gasket but directly into the aluminum case. You have to add the gasket and pan thickness to the length of the fastener or you will pull threads.
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Re: Trans pan bolts mess
[Re: A12]
#3087714
10/20/22 09:02 AM
10/20/22 09:02 AM
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Joined: May 2019
Posts: 6,175 nowhere
Sniper
master
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master
Joined: May 2019
Posts: 6,175
nowhere
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The case of the of I didn't use a torque wrench and who the #3LL ever does when putting pan bolts on so chalk it up to "damn I hate when that happens and now I have to Helicoil them". I use a torque wrench on them. I spent many hours repairing aluminum threads when I was in the Navy because hamfisted sailors reefed down on them. And I can guarantee that you can rip out aluminum threads even if you have 8mm of thread engaged. Just keep tightening and it will happen. Now if it were steel on steel, or iron, you'd like snap the bolt, but not on aluminum.
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Re: Trans pan bolts mess
[Re: Sniper]
#3087818
10/20/22 02:28 PM
10/20/22 02:28 PM
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Joined: Sep 2003
Posts: 19,239 north of coder
moparx
"Butt Crack Bob"
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"Butt Crack Bob"
Joined: Sep 2003
Posts: 19,239
north of coder
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The case of the of I didn't use a torque wrench and who the #3LL ever does when putting pan bolts on so chalk it up to "damn I hate when that happens and now I have to Helicoil them". I use a torque wrench on them. I spent many hours repairing aluminum threads when I was in the Navy because hamfisted sailors reefed down on them. And I can guarantee that you can rip out aluminum threads even if you have 8mm of thread engaged. Just keep tightening and it will happen. Now if it were steel on steel, or iron, you'd like snap the bolt, but not on aluminum. i always say : "tighten 'em up till they strip or break, then back 'em off 1/2 a turn"...........
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