Looking for an Automotive Engineer

[Merkava_4]

At this point, I'll settle for any kind of engineer. I've been scouring the internet trying to find a torque table for a GM 4T65E fluid pan. I've found one for a GM 4T80E, but nothing for the 4T65E. I would be extremely grateful to anyone who can come up with the correct torque sequence. FEL-PRO calls it a "torque table."

GM 4T80E

GM 4T65E

 

[tom slick]

You just need to torque the bolts in an "X" pattern as much as possible.
Notice in the example pattern is
1 upper left
2 lower right
3 lower left
4 upper right
5 upper left
6 lower right
7 lower left
8 upper right
and on and on.

 

[Kuato]

Wow. Merkava IMHO you are WAY overthinking this. The order of the trans pan bolts being tightened is in no way as important as, say, the head on the engine block.

As I commented in your other thread, I've never torqued my trans pan bolts, (recommending a pattern for you) and have never had a leak or broken or deformed part.

There may very well be a factory recommended pattern for tightening; perhaps you should try to pick up a Chilton's repair manual for your vehicle.

 

[PHANI1]

This may help -

Bottom Pan Bolts (mid 98+) M6 X 1.0 X 17 10

found here: http://tripleedgeperformance.com/4T65E-Tech-Info.html

 

[Merkava_4]

tom slick:

Can you come up with a "firing order" for this gasket? I went ahead and numbered the holes for you here:

 

[randomhero439]

1
12
8
16
2
13
9
17
3
14
10
18
4
15
11
19
5
16
20
6
7

 

[Merkava_4]

randomhero439:

Please fix it. You've got 16 listed twice.

 

[Shannow]

20 holes helps...with a pan gasket, you want to trap spots, then mid point of sides then mid point of mid point.

Pick 1-11, or 1-12 as your start point, say 2-12, do them

Halve the gap, say 7-17, pick another gap, say 4-14, then it's "opposite", say 10-20...keep splitting the differences, keeping to the area you were longest away from...if you had five, you'd want to draw a pentagram so to speak.

2
12
7
17
4
14
10
20
15
5
13
3
18
8
1
11
16
6
19
9

This sort of gasket is different to a head gasket, where you need to trap the centre, and squeeze to the outside.

 

[OneEyeJack]

You compulsive attitude toward this issue prompted me to call a friend of mine who is a Senior Manufacturing Engineer at a factor that designs and makes all kinds of transmissions. He said that he is very familiar with this transmission and that any of those cross pattern ideas will work just fine and the real problem is over torquing. He said to stick to the factory specs and don't try to out engineer the engineers. Just go around the pattern in 2 or 3 steps bring the torque to the final spec. He also said that in your case do not attempt this on the night of a full moon or after consuming an energy drink (lol). And if you want a correct torque reading clean both the male and female threads and make sure they are completely dry before attempting to reassemble your transmission. After reading your first post he said he assumes that he does not have to say anything about being clean, neat and careful will completing this task. He also said that you will probably feel compelled to over torque the bolts and if you absolutely must screw up the job than only go 2 pounds over the spec after being careful to make sure that all the threads are absolutely clean, clean, clean.

 

[Ken_W]

I agree with the points above that the exact sequence is not as important as the fact that you keep crossing from one side to the other, and snug all bolts first before giving them the final torque on a second pass.

Tighten all the bolts to about 10 foot-pounds (120 in-lbs) of torque if you have the factory rubber and steel gasket. If you are using a cork gasket, tighten the bolts to about 7 foot-pounds (84 in-lbs). If you don't have a torque wrench, use a 1/4"-drive handle and an extension that passes through your two middle fingers. Tighten by just twisting your fist. It will be difficult to over-tighten that way.

 

[PandaBear]

As Tom Slick said, you are over thinking. If you are that concern about tightening pattern, do it in many, many passes and let's say tighten 1/4 turn at a time across all bolts/nuts until it is up to torque spec. The amount of time to think about this and post on the net would let you tighten them in 16 passes already.

 

[Kuato]

Originally Posted By: Merkava_4
randomhero439:

Please fix it. You've got 16 listed twice.

Come on. Everyone knows that bolt #16 requires twice as much torque.

 

[Merkava_4]

Originally Posted By: PandaBear
As Tom Slick said, you are over thinking.


That's just it, I don't want to think about it. I just want to look
at a torque table that tells me which bolt to torque next.

 

[expat]

Originally Posted By: Merkava_4
Originally Posted By: PandaBear
As Tom Slick said, you are over thinking.


That's just it, I don't want to think about it. I just want to look
at a torque table that tells me which bolt to torque next.

You should not be working on the verhicle if you are not thinking!

The point is, to secure the pan without creatin distortion of over tightening the bolts.
Without a guide some idiot might fully tighten one nut, the move on to the nut next to it, and so on, in a circular pattern
This could cause the pan to warp or even crack.
To safe guard against idiots like this, manuals advise a proper engineering practice of torquing in a cross patern.
Honestly, with many, evenly distributed fasteners like you have, one cross pattern is as good as another.

I have worked in a Dept where maintenance manuals are written. Believe me, many directions are made up just from common engineering practice ie. torque in a cross pattern. If something proves to be wrong, or requires an exception, a service bulletin is issued.

If it makes you feel better, many 'so called' mechanics out there would just zip up those fasteners with an air wrench, willy nilly without a second thought.

Please! If you keep on with this, the proffesonal help 'you need' should not come from an engineer.

 

[Merkava_4]

Originally Posted By: expat

Please! If you keep on with this, the proffesonal help 'you need' should not come from an engineer.

 

[danthaman1980]

Originally Posted By: Shannow
20 holes helps...with a pan gasket, you want to trap spots, then mid point of sides then mid point of mid point.

Pick 1-11, or 1-12 as your start point, say 2-12, do them

Halve the gap, say 7-17, pick another gap, say 4-14, then it's "opposite", say 10-20...keep splitting the differences, keeping to the area you were longest away from...if you had five, you'd want to draw a pentagram so to speak.

2
12
7
17
4
14
10
20
15
5
13
3
18
8
1
11
16
6
19
9

This sort of gasket is different to a head gasket, where you need to trap the centre, and squeeze to the outside.


^This order.

Step 1: 1/4 torque
Step 2: 1/2 torque
Step 3: Full torque

But really, on a trans pan with a rubber gasket, it doesn't matter THAT much, as long as you tighten the first 4 to 8 in an X pattern and torque them all down gradually in 2 to 3 passes.

 

[expat]

Originally Posted By: danthaman1980
Originally Posted By: Shannow
20 holes helps...with a pan gasket, you want to trap spots, then mid point of sides then mid point of mid point.

Pick 1-11, or 1-12 as your start point, say 2-12, do them

Halve the gap, say 7-17, pick another gap, say 4-14, then it's "opposite", say 10-20...keep splitting the differences, keeping to the area you were longest away from...if you had five, you'd want to draw a pentagram so to speak.

2
12
7
17
4
14
10
20
15
5
13
3
18
8
1
11
16
6
19
9

This sort of gasket is different to a head gasket, where you need to trap the centre, and squeeze to the outside.


^This order.

Step 1: 1/4 torque
Step 2: 1/2 torque
Step 3: Full torque

But really, on a trans pan with a rubber gasket, it doesn't matter THAT much, as long as you tighten the first 4 to 8 in an X pattern and torque them all down gradually in 2 to 3 passes.


Please, don't encourage him.... next he'll want a torque pattern for his wheel lug nuts.

 

[L_Sludger]

incredible. every time i've done a trans pan i never paid attention to the sequence that the bolts were tightened, and i've done it about a dozen times.

 

[Merkava_4]

Originally Posted By: expat

Please, don't encourage him.... next he'll want a torque pattern for his wheel lug nuts.


That's easy, I use a star pattern for that.

 

[Merkava_4]

Using Shannow's firing order, I came up with this: