Engine/Transmission (1998.5 - 2002) Stripped transmission pan bolts?

[Turbo Terry]

First let me say that it is not my intention to make this a witch hunt or to blame anybody outright. My hope is to help someone else with this heads-up and at the same time resolve my problem and obtain a repair. The story- My truck is a 1999 and sometime after buying it I decided to install a Mag-Hytec transmission pan to make servicing easier. The only things to note is I did read the directions carefully ,used the cork gasket provided and properly torqed the pan bolts to ( 20 ft lbs. per instructins). The truck is now 4 years old and 38,000 miles. The pan has been removed about 6 times. The first 2 times I use new cork gaskets but found that to be a pain scrapping gaskets and the gasket was always torn and crushed. So I went to Car-Quest and got a neopreme gasket which is reusable. In March of 2002 I had the pan dropped and valve body replaced by a transmission shop. I left a large note with 2 gallons of ATF fluid, a new filter and a new neopreme gasket just in case. The note said please replace filter and reuse the gasket your call . The truck came back with new gasket on the seat. The note said please retorque pan bolts to ( 20 Foot lbs. ) Big letters. Dropped truck off went to work and picked up in pm after they were closed. I did have to add some atf in the next day or two (Normal). I honestly cannot remember if I took a creeper and torque wrench and did a retorque as was always what I have done before after the pan was down. Anyway yesterday I dropped the pan to do some maintenance. While removing the bolts I noticed some (3 or 4) were very loose but never thout much about it at the time as I,ve had loose ones before. I finished my work ,put the pan back on using the old gasket. Of course on the retorqe (20 foot lbs. ) I found one bolt that would not take on the threads and two that would not retorque. Three out of 14 are stripped. I ASSUME that the transmission tech used a air wrench on the pan install back in March ??? and realized his mistake (gun set to high whatever) and failed to come clean. If he had used a torque wrench and found three stripped and said so he could have put the blame back on me??? Anyway do you think I have any groud to stand on with transmission shop or not to bother? BUT most importantly what are my options to make repairs. I need some ideas. Thanks

 

[tmacc]

TT,

I have use HeliCoils to repair stripped or damaged alum. threads many time. Alum just doesn't seem to hold up to repeated re-torqueing of screws and bolts. You should be able to fine them at an auto parts store. The kit usually comes w/ a tap and a installation tool. Shouldn't take more than about 1 hr for 3 bolts. HTH

Tom

 

[DavidC]

Studs

After repairing with Helicoil would replacing the bolts with studs and lock tite be a viable option?. Figuring the threads in the transmission would not get all the abuse of in and out all the time. Just an idea, I personally have not tried this yet.

 

[Turbo Terry]

I like these two ideas especially the idea of double nutting a stud bolt and running it into a Heli-Coil with blue loctite then they could be replaced as they wore or threads wore down. I think I would just do the 3 bad ones and leave the other working one for now? We need some input from a transmission guy as to how they would do it. Thanks

 

[JWhitcomb]

I don't have an auto so I have no idea of how often you need to re torque. I don't think I would use Loc Tite. It seems to me it is pretty easy to re torque. You need to find out how long a Heli Coil to use from some one who has done it. Four or five thread engagement gives as much holding power as any more. You also have the option of putting in the locking Heli Coils.

 

[DavidC]

The Lock tite was for the studs to keep them from turning while using nuts at the pan. Personally if I were going to use the studs and I already had some stripped threads you are already going to have to drain the fluid and remove the pan because the helicoil is going to involve drilling an oversize hole for the helicoil to screw into. If your going to this much trouble you might as well stud them all and not have to do it all over again the next time.

The most important part of this operation is holding the drill perpendicular to the existing hole otherwise the stud or bolt will tighten at a slight angle (not good). Anybody have a good home made jig assembly to accomplish this and be sure the helicoil is not installed at an angle?

 

[JWhitcomb]

Opps, like I said I don't have an auto and don't know how the pan goes on. A jig should be quick to make out of some one inch alum.

 

[tmacc]

The parts that I used HeliCoils on are parts that are removed periodically for mantinance. The helicoil is made from SS, so I would think It would hold up for a while. How many of us in our youth had to use them on our air-cool VW heads for the spark plug. (Not me, but I learn from a friend's mistake. Yeah... that's it..... a friend) Studs sound like a pretty good idea for this application, but might be overkill.

As far as drilling the hole straight. The easiest way to do this w/o a gig is to drill the hole in steps. By drilling the holes in two or even three steps the drill bit "almost" self aligns itself in the hole. Now, one big word of caution here. When drilling a slow speed hole in alum. the bit tends to grab and suck the drill bit into the hole. That's why I would suggest drilling in steps. Your removing small amounts of alum. and it's easier to control the drill. FWIW A cordless drill is my choice for this kind of stuff.

I agree w/ the above post. A gig would be easy to fabricate. It would be nice to have a gig w/ a elongated slot that you could possition over the hole by bolting it into the ajoining hole.

 

[inarush76]

TT...OUCH!

Hate to hear about the bolts. Heli-coils will work fine for the repair. Drilling straight is important. Use lube on drill and tap. Dodge transmissions have always had a tendency to lose threads in pan bolts. This usually is brought on by impact tools or over torque. I opened one of the Mag-Hytec pans I have on hand and double checked the torque recommendations. The installation sheet shows 12-16 ft. lbs(144-192inlb. ) The 20 ftlb you have been using is a bit high. Though it is likely that the pan was installed with an impact. I hope your repair goes well and without complications.



James

DTT dealer/installer/builder

near Dallas,TX

 

[Snow man]

Terry, I hope you get those helicoils in straight. I use a milwalkee 18 Volt cordless drill for all my pan,and valve body work,I have the 3/8",and 1/4 adapters,even though i have air tools, i use the cordless,its much easier,more forgiving, and the clutch lets you work as fast as air tools, without risking strippping VB bolts,or pan bolts.

 

[Turbo Terry]

My Mag-Hytec instructions show 20 lbs,maybe this should be clarified with Roy as this could be some of the problem? Thanks for all the info. This will be in the search for when someone else needs it . Keep it coming. I,ll call Roy tommorrow. Great guy I like talking to him. TT

 

[Huff N Puff]

Keep it simple

Your holes in the trans are already set for a 3\8" coarse tap. Tap the stripped holes to 3\8" all you might have to do, is drill the pan to fit the new bolts. If you want all the bolts match,do them all, the new bigger bolts are less likely to strip. Dont be so quick to point the finger,Its not unusual for electrolosis to sieze the threads to the bolts on the way out.

 

[lgibson]

Speaking as a R&R man, I have seen many many pan bolts stripped out. I always used heli-coils for repairing them and they worked ok. Also I will NEVER use anything but cork gaskets. As long as the pan and transmission case is dry, these gaskets will not leak. The neopreme gaskets needs to be tighten more or they will leak. Remember it is only alum. and the tighter and more often the bolts are installed the weaker it gets.



Twenty pounds does seem too much, but I never torqued any pans down. I always make sure the pan lip is flat and not bent up at the bolt holes. I use only cork gaskets and tighten them using a speed handle, till I can see and feel the cork start to compress. I would not use air tools for tighting pan bolts either. I never stripped out a bolt hole or had a transmission pan leak in over 11 yrs.