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trans leaking, any additive to stop it

mudd

Senior Member
Offline
have a rebuilt trans with overdrive, thing still leaks, does anybody know of an additive to put in to get these things to stop dripping oil all over the floor?
 
yup

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Most Japanese OEM's use it (Kawabond, Yamabond, Hondabond etc) and it is probably the best sealant I have come across.

You also will have to install a seal on the input shaft if there isn't one already and modify the dipstick to have an oring rather than the felt thingy.

My trans is still completely leak free after several hours dyno running- except for a small weep coming down the tailshaft nut thread as I forgot to put thread sealant in there. Got to pull it all apart now anyway to fix the synchro cones.

Sorry, probably not the answer you were after eh.

Andy.
 
Yes, I wouldn't add anything to the oil. "Stop Leak" products swell seals and I don't know how that would react with the wet clutch of the OD...not to mention that those products won't really help if it's coming from the input shaft seal, output shaft seal or at all if it's coming from either side of the brake ring in the OD because there is no gasket in there for it to swell.

I had seen and thought about trying this product for my leaky trans/OD which you apply from the outside:

https://www.permatex.com/resource_auto_archive/pr_auto_07252007.htm

There's a cheesy infomercial for a similar product where a guy sprays it on a screen bottom boat and floats around in it but I figured that since this was made by Permatex it might actually work. It says "goes on clear" and would only assume it stays clear or they wouldn't even mention it. The only thing like with anything you'd put on from the outside would be if you could get the area clean enough for it to take.

Just an idea...
 
Hi Mudd,

Yes, don't add anything to the oil, saying that, you do know that the trans uses 30 wt oil, not 90 wt gear lube? I say that as I had no idea until I had to remove the trans/OD and replace the piston, rings, and liner due the DPO's use of 90 wt. The clutch was jammed so hard it had to be pryed apart...

Also, and you might look for this, mine had a warped rear housing on the OD due to the wreck it had been in. Apparently the trans locating rod/bushing can warp the case if the shunt is severe enough. The engine/trans has so much movement on the motormounts, it will bend the front frame crossmember too. I was able to chuck the case in a lathe and true up the fit without removing too much material. It went back together fine, and now doesn't leak.

Where is yours leaking from?? I know the drain plug on the OD is famous for leaking, but that should be able to be fixed readily. Otherwise its the seals or the case gaskets or ??

Hope this helps....Jerry Rude

BJ8/Lotus Europa TCS
 
cant tell really where its coming from, seem like the top somewhere. after driving, it will drip for about a day, then after i clean it up, nothing, so i am assuming that its dripping down from the top someplace, hard to tell without jacking it way up in the air and getting under it.
 
Flatten a big cardboard box and drive over it after a long drive and let the car sit for a couple hours. Then, find the spots and draw an imaginary vertical line orthogonal to the center of the spot(s). At the end of line will be the approximate location of the leak source.

My bet is you're leaking from a) the hole at the bottom of the bellhousing (common) and/or b) the big brass nut on the bottom of the O/D (also common). Obviously, if the spots are elsewhere then you have gasket or seal issues.
 
Flatten a big cardboard box and drive over it after a long drive and let the car sit for a couple hours. Then, find the spots and draw an imaginary vertical line orthogonal to the center of the spot(s). At the end of line will be the approximate location of the leak source.

good advice, ill try that, i drove it without the overdrive, didnt see any oil on the ground, so im thinking its coming from the OD someplace

2 repair guys said they use 20/50 oil in the trans, is that correct?
 
mudd said:
... 2 repair guys said they use 20/50 oil in the trans, is that correct?

I used 20W-50 oil for years with no problems. A few years I decided to try synthetic (Redline MT-90) to see if the O/D would engage a little quicker. It did, but I was totally surprised that shifting seemed smoother as well. Also, when I did finally change the MT-90 it appeared there was less of the finely ground brass 'shake' in suspension.

Others recommend Redline MTL, which is a little thinner. The main downside is cost and the synthetic is almost impossible to contain. I decided to live with some leakage and just top up more often.

Note the 'book' calls for straight 30W 'non-detergent,' although IIRC my BJ8 shop manual allows 20W-50 as well.
 
I used some stop leak stuff I got at auto parts store in a Ford truck with an auto transmission. Stopped the leaks and the truck ran with no problems for a number of years. Of course the transmission had transmission fluid and not oil in it. The stuff supposedly swells the seals and gaskets.
 
seems like the trans rear seal is leaking, anybody have a fix for this, other than pulling the interior apart and removing the trans to replace the seal???

sad part is, supposedly the seal is new.

thanks
 
You can replace the rear seal with the transmission in place (at least I did with my BN2). You need a small slide hammer that has an adapter to hold a small sheet metal screw on the end. With the driveshaft removed or at least out of the way you drill a couple of small holes in the sheet metal of the seal (look at your new seal to see what I mean). You thread the screw into one of the holes and give a few taps with the slide hammer; if the seal starts to come out put the screw 180 degrees from the first hole and repeat until the seal pops out. Install the new seal with the sealant of your choice on the OD of the seal (sparingly)and tap it into place with an appropriately sized socket( be careful not to deform the seal when "tapping " it into place). I have welded a nut onto the adjuster of a pair of vice grips and thread my slide hammer on so I have a slide hammer with a vice grip at the end of it. I use the vice grip to grab the screw. Your mileage may vary but it worked for me. You might try gently getting under the lip of the seal with a cotter key puller and pry it out that way. I've done that too but you must be careful not to damage the surface that the seal runs on.
 
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