86 with 4+3 tranny -- stripped plug on overdrive unit

[Fatchy]

The transmission fill plug on the overdrive unit of the 4+3 is stripped & I can't get it out. I bought the vette in the spring & went to change the fluid. The bolt was already rounded off & I tried using vise grips & a pipe wrench but could not budge it. I ended up filling the fluid thru the radiator cooling return line but couldn't get in all the fluid it calls for. I think the plug is aluminum.

Any ideas?

 

[Hib Halverson]

The transmission fill plug on the overdrive unit of the 4+3 is stripped & I can't get it out. I bought the vette in the spring & went to change the fluid. The bolt was already rounded off & I tried using vise grips & a pipe wrench but could not budge it. I ended up filling the fluid thru the radiator cooling return line but couldn't get in all the fluid it calls for. I think the plug is aluminum.

Any ideas?

Just so I understand, you were able to get a "bite" on what's left of the plug with the visegrips but you could not loosen the plug? Or did you just round it off, more?

 

[Fatchy]

Just so I understand, you were able to get a "bite" on what's left of the plug with the visegrips but you could not loosen the plug? Or did you just round it off, more?

I am able to get a "bite" on what's left of the plug but I can not get the plug to turn.....I just end up stripping the plug more.

 

[Hib Halverson]

I am able to get a "bite" on what's left of the plug but I can not get the plug to turn.....I just end up stripping the plug more.

Hmmm. That's a big heap of not good.

Hopefully, some other of the Doug Nash experts out there will contribute but, if it were me, here's what I'd do.

Drain the overdrive unit, drop the OD oil pan and remove the filter assembly. Drill the fill plug and install a big EZ-out and attempt to remove what's left of it. Once the plug is out, Inspect the threads in the OD case and repair if necessary. Flush the chips out of the overdrive unit by spraying WD40, brake clean or some other solvent or light oil.

Reinstall the filter and the OD pan. Fill the overdrive and install a new fill plug. Drive the car for a short road test to operate the OD pump.

Drain the OD again and this time, change the filter. Refill the overdrive to the proper level.

 

[WhalePirot]

Ouch! Is it a beach car and corroded?

I have had mixed luck with easy outs; breaking as often as not. Being very hard, they're difficult to drill out if broken.

I'd try heating the plug, with the hottest burning gas you have, repeatedly, carefully and quickly; not the case however. Thermal expansion may help break any corrosion bonding. Then, I'd get as much penetrating oil, or the homemade equivalent, to soak in for as long as you can wait. It'd be hard to let it soak too long and too much would only drip.. small loss.

Then try the easy out. The larger the hole and tool the better the odds of it working. Hopefully, you will not have to pull the unit and have the drain redrilled and tapped.

The most common way to make homemade penetrating oil is to combine acetone and Automatic Transition Fluid (ATF).

Patience here will be very important, especially letting any lube work its way in.

 

[Fatchy]

I don't see much corrosion underneath the car....only 59k miles. I've already tried penetrating oil a couple of times, no luck.

I'll try heating the plug & if that doesn't work, I'll get the drill & try my luck.

My back up plan is to jack the front end way up & fill the transmission thru the transmission cooler return line fitting.

 

[WhalePirot]

It's just that I saw how quickly salty air or sand (Myrtle Beach sand khana) could corrode.

These guys may be helpful: Racing Parts for Import and Domestic Street Racing Cars

I have called them & was pleased, though my unit was redone by 5-speeds in Boca Raton, who sold them the biz and parts.

I feel your pain and you probably already saw the few other posts on this. The Nash is a good unit but needs proper maintenance and fluid quantity, which is set by filling until it runs out the hole. I suppose you could fill it by the jacking method, then set the car back down and let it drain.

 

[steveb01z06]

I had a similar issue with a transmission drain plug on a truck. I had tried the EZ Out with no luck. I I took the pan to a shop in desperation and he did what I had considered but didn't try: he used a pnuematic impact chissel at an angle so that some of the force was trying to loosen the bolt while the chissel was digging into the bolt head so that it wouldn't slip. I would guess that the angle was around 45 degrees.

 

[alwaze1]

pipe wrench

The transmission fill plug on the overdrive unit of the 4+3 is stripped & I can't get it out. I bought the vette in the spring & went to change the fluid. The bolt was already rounded off & I tried using vise grips & a pipe wrench but could not budge it. I ended up filling the fluid thru the radiator cooling return line but couldn't get in all the fluid it calls for. I think the plug is aluminum.

Any ideas?

If you buy a new pipe wrench it should work. If the plug is stripped round take a grinder and grind a couple of flat sides. With a new wrench with new teeth it should get it done. I hope you get it!!!

 

[kpic]

Drill a small hole in the center, it heats the bolt and also allows the bolt to contract when you apply force.

If that doesn't work, using a drill index, progressively drill the hole larger and larger; you may be able to tap it out or even break it into pieces.

Same as Whalepoint, I've broken too many EZ-outs.

Good luck

 

[targatom]

freon spray

You may want to heat the area surrounding the plug, then hit the plug itself with freon spray , hardware stores can order a spray can of it. This should expand the case, and shrink the plug, breaking whatever corrosion is there. All the other guys had good info too, but this is an additional thing to try.

 

[Hib Halverson]

You guys know this is a three year old thread...right?

 

[targatom]

three yr old, yes

You guys know this is a three year old thread...right?

Hi Yes I knew that, but since I search old thread s for info that I can use, perhaps someone else can use the info that I provided since it hadnt been mentioned before.