Bonded torqueflite pan gasket

B

Bob Prohaska

Member
The torqueflite repaired here
http://forums.IHPartsAmerica.com/showthread.php?t=588&page=13

Has worked fine for the past year and a half, but about six
months ago it developed a fairly serious leak, seemingly at the
pan gasket. The gasket is a neoprene rubber sheet, close to
an eighth of an inch thick. It sealed perfectly with very modest
torque on the bolts to start with, but now it won't seal even with
the full rated 10 ft-lbs on the pan bolts. At the moment it leaks
a few drops per day when standing, so the car's driveable but
makes a mess.

In the meantime, I acquired from the local chrysler dealer a
modern replacement gasket, a fancy molded thing with little
rubber ridges on both sides, costing around $30. It seems to be
referred to as a "bonded re-usable gasket" and is marked with
the chrysler diamond logo and three numbers:
02464324ac
7119/03
72523c

does anybody have experience with this gasket that they're
willing to share? For example, is the torque spec the same 10
ft-lbs? I tried searching the web and found no reference data.

Given that the flat rubber gasket seemed in good shape and
sealed very well for a year it's really puzzling to have a leak
develop without provocation in about one year.

Any thoughts appreciated, and thanks for reading!

Bob prohaska
 
I use those new gaskets, they are great.

I also buy the longer chrysler pan bolts, as the gasket is thicker and the longer bolts are recommended.

10-12 ft. Lbs. Is fine on torque. Do not over-torque!
 
That's a most encouraging testimonial! When I first saw
the gasket I was somewhat surprised by how elaborate it
seemed to be, but maybe there's some method in the madness.

Did you use any lubricants or sealants on the gasket?

Did you take any special precautions to flatten or pre-form
the pan flange? I've wondered it if might help to put a slight
downward bend in the flange, maybe a degree or two, so that
the innermost rim touches before the outer edge. The existing
pan isn't badly distorted, but some distortion is visible. It didn't
look bad enough to interfere with the flat rubber gasket, and wasn't,
at least initially.

Thanks for replying!

Bob prohaska
 
No sealant is used.
Mating surfaces clean and dry, remove old sealant residue.
Ensure pan is flat to provide full mating surface to gasket.
Ensure pan is flat at each bolt hole area.
It's about as basic as you can get.

Again, I recommend the new longer pan bolts from the local mopar dealer.
 
Both the pan and transmission surface are clean, I'll take a very
close look at the pan flange. It looked "flat enough" but it very
certainly isn't perfect. Seems unlikely to be cracked, but I
suppose that's an outside possibility.

My usual practice is to grease gasket surfaces if there's no
sealant involved.

Thank you very much!

Bob prohaska
 
Well, the bonded pan gasket didn't fix the leak, and after a long time
I decided to try again. That still leaked, so I bought a new pan from
IHPA (the plain steel version, not chrome) and tried to install it.

The pan seems to hang up (bolts are finger tight, but the gasket still
wiggles up and down about an eighth of an inch. When I measured
the pan depth, it's about a sixteenth shallower than the original,
which I'm pretty sure is factory OEM.

An eighth at the edge seems to about agree with a sixteenth halfway
across and the obvious thing to interfere is the filter. The filter is stock
from NAPA, the gasket is OEM from the local Ram dealer and has a
Chrysler logo on it, so I'm fairly confident both are with the bounds of
normal fit.

It's _really_ tempting to try bending the filter a little, and maybe spring
the pan a bit (it's rather limber) but before doing that it seems wise to
ask if anybody's seen this problem before and how they solved it.

Thanks for reading and any guidance!
 
The interference turned out to be the magnetic drain plug against the
corner of the filter. It was only about a tenth of an inch, so I just bent
the filter up a little and everything went together reasonably well.

The gasket has two "lines" of sealing surface, but it looks to me as
if only the inner one needs to seal. In fact the pan doesn't even touch
the outer sealing line at the rear center of the pan. It seems to be holding
ATF at only four foot-pounds of torque, but it'll take a couple of days to
be sure.

Does the IHPA Torqueflite pan call for a particular filter? I don't mind
bending things a little, but if there's a better-fitting part I'd like to know.

Thanks for reading!

bob prohaska
 
Bob Prohaska said:
It seems to be holding
ATF at only four foot-pounds of torque, but it'll take a couple of days to
be sure.


bob prohaska
Click to expand...

The new pan seemed to seat very evenly at four foot pounds, but it leaked
anyway. I've been cinching the bolts up in .4 ft-lb increments, and the
leaks diminish a little at each tightening.

At 10 ft-lbs there's still a trace of leakage at the right-side front and rear
corners, enough to show on a white rag in six hours. The bolts are now
at 10.4 ft-lbs with a fresh witness rag

Anybody else been through a drill like this? I'm surprised at having to make
the bolts so tight, and wondering if I'm doing something else wrong.

Thanks for reading, and any guidance.

bob prohaska
 
The last remaining leak seems to be coming from the low/reverse servo
pivot pin hole. I know the "correct" fix is to pull the pan, pull the t-case,
tailhousing, remove the pin and replace the o-ring. That's a big job for a
small part and I really hate to disturb the trans, which works perfectly.

As a preliminary, I'm really tempted to try some sort of a temporary cover
or plug to verify that this really is the source of the leak. Access is not
good, but a wad of epoxy putty tucked under the retainer tab on the tail
housing might stay in place for a while, hopefully until there's another
reason to take the car apart.

It takes a couple of days for the torque converter to drain back enough to
cause a leak, so I think the case can be cleaned and will stay clean long
enough to give the sealant time to cure. I'm uncertain what sort of glue,
putty or sealant to use. Maybe non-hardening Permatex number 2 gasket
adhesive?

If anybody has thoughts, pro or con, I'd be grateful for them.

Thanks for reading,

bob prohaska
 
After thinking things over, I'm starting to wonder if a deep pan and pickup
extension might solve the problem until it's time to remove the trans for
other reasons. That would allow the fluid level to remain below the pivot
pin opening even with the torque converter drained entirely.

IHPA sells a deep pan but makes no mention of a pickup extension,
which is necessary for my purposes; is an extension to fit this pan
available, from IPHA or other vendors?

https://www.ihpartsamerica.com/store/TRANS-727-PAN-DEEP.html

It also notes
May have driveshaft clearance issues when used on a stock lifted
Scout II.

Is this a concern for normal roadgoing? The Scout is stock and
_not_ lifted. The OEM pan is 1.25" deep at the front edge and tapers
shallower to the back. A pan twice as deep with the same taper looks
like it'll fit

Thanks for reading, any thoughts appreciated!

bob prohaska
 
With some hesitation I decided to epoxy the opening where the
low/reverse pivot shaft resides. For now the leak seems to be
stopped, buying me some time to look for a shop to service the
trans permanently. Given its age and mileage that will probably
take the form of an overhaul even though the trans works perfectly.

If anybody is willing to suggest a good shop in the Sacramento CA
area it would be much appreciated.

There are a few more details at
http://www.zefox.net/~bp/scouttransleak/

Thanks for reading,

bob prohaska
 
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