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T18 oil leak out the tower

T18 oil leak out the tower

Dlowe

Jeeper
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Location
Washington
Vehicle(s)
1972 CJ5 - 258, T18, D20
What's the answer to stopping gear oil from leaking out the top of the tower?
 
Make sure your vent is "breathing"
 
What's the answer to stopping gear oil from leaking out the top of the tower?


Going to take a guess... you might be foaming up. If you have not changed the gear lube or you play in water..... time for a fluids change....

If the fluid comes out like choc milk its full of water and might have some rusting going on...

Also many places only carry GL5 gear lube and GL4 is the speced product and will work better.. I have also found the AMSOIL MTF, manual Transmission fluid, works better in our old jeep Transmission than even the the GL4... So I guess not all fluids are equal and I know the GL5 can hose you up pretty well.



Here is some verbage on where to get the GL4 Gear Lube and the right stuff for our Jeep Transmission .... Use it in the Transfer Case also...

Here is a POST from me a few years ago.... I just copied and pasted here so hope nobody minds. YOU WILL FIND NOTHING BUT GL5 GEAR LUBE ON THE STORE SHELVES, NOTHING BUT.... The GL5 GEAR LUBE is the wrong fluid for old JEEP CJ Manual Transmissions and Transfer Cases, can also cause the SYNCROS to start rattle/noise and not work well or shift well. GL5 HAS THE WRONG.... LUBRICATION PROPERTIES.... AND.... IT IS CORROSIVE TO YELLOW METALS USED IN MANUAL TRANSMISSIONS. Some have posted, many posted, they could hardly shift after some time. Changed to GL4 and got better and quieter. I have done this dozens of times with great results.

So Please copy this to your hard drive and spread the word. This could stop a lot of JEEP MANUAL Transmission FROM FAILURE AND REBUILD BEFORE THEIR TIME. TRY IT YOU WILL SEE.................

The confusion with the AMSOIL product its rated as oil viscosity and not Gear Lube viscosity. The TWO OIL VISCOSITY SCALES cross or equal at these weights…..AMSOIL MTF is what I am going to change to since I do not WATER CROSS so the installed life will be of benefit. I currently have the Napa GL4 installed and very pleased with the correction of operation and is getting even better over time…. Almost no syncro rattle now

THE AMSOIL MARINE GEAR LUBE CAN ALSO BE USED FOR......... GL4 GEAR LUBE, it meets the GL4 spec, it can absorb more water before oil failure. SO... for those of you that play in the water alot that may be a good choice.


This info has been posted lots….. and many times on the forums. MOST of the Jeep Field Service Manuals say use GL4….. the only place Jeep messed it up was 1982 they said GL5 and had INDUSTRY RECALL ON ALL MODELS and changed the gear lubes and transmissions left and right…. Or very often.

The Amsoil White paper on gear lubes is a very good read.

The Novak Web site does have a little blurb on gear lubes/Transmission and its very confusing, not well written, and its leading many down the wrong path. I wish Novak would rewrite and update their info.

Gl4 and GL5 are not the same and not interchangeable…….. their applications are different…. Their properties are different….


It your syncors rattling. The gear lube on the shelves is GL5 and is a product made for the pumpkins of these big large towing capacity tow rigs. The GL5 has the wrong lubrication properties and is corrosive to the yellow metals in manual transmisisons. All the BorgWarner Transmissions in the older Jeeps should use Gear Lube.

The RIGHT GEAR LUBE is GL4...... GL4...... GL4.... Napa Sells it, call them and ask them to order you 1-2 gallons and it’s like $25 a gallon….. when I first suggested Napa it was $15/gal now the price has almost doubled.

IN my case……Took out GL5 and put in Napa’s Gl4……You will also find After 50 to 100 miles it will start shifting better and should start to get quite. My T-18 did the same thing after I put the Gear Lube from the shelf.... it was GL5 and started shifting harder the the syncros starting rattle. Now almost silent and shift much better and its 32 years old.

Alternaitves Amsoil Syncromesh is a GL4 or Mobil 1 were both rated very high and and some of the least expensive on the list.

Bromgarrds Farm Stores, IA, NE, Co, Midwest area also have a GL4 gear lube. Sell 2.5 gal container for like $27.


I have posted this up many times, many folks amazed with results. Frankly I am SHOCKED another fluid bad for our Little Jeeps ALL OVER THE SHELVES. I HAVE LOOKED YOU WILL ONLY FIND GL5 ON THE SHELVES. Good for your pumkins but not for the Transmission /transfer. Also add a magnet to both drain plugs to catch the metal particle. I also took a "stick magnet" and rubbed the bottom of Transmission /Transmission and got more out that way.

NAPA
SAE 85w90 Gear Oil GL4 (also meets GL3)
Part #SL24239
Mfg By Sta-Lube, sibisdary of CRC Industries
Bar Code 72213-24239
$25/gallon, phone order take 1-2 days to arrive, then pick it up, easy

I would also consider Amsoil MTF Syncromesh GL4 or the Mobil 1 Gear Lubes they were tops in performance and lower in cost that most. $8-10/quart.





PS
Use GL5 Gear Lube in your Pumpkins and follow any recommendations for Limited slip or locker additives.






APPLICATIONS For GL4 and Amsoil MTF Gear Lube their GL4
Recommended for automotive and light-truck applications that require synchromesh Transmission fluid. Applications include manual transmissions and transaxles such as New Venture NV T350, NV 1500, NV 2550, NV 3500, NV 3550, NV 5600, and Tremec T-4 , T-5 , T-18 , T56, T-176 , TKO500, TKO600, TR 3450 and TR 3550. Replaces MTF-94 fluid for Land Rover, MG, and Mini Cooper. Replaces Honda Genuine MTF fluid for manual transaxles and Texaco MTX fluid. Not for use in engines, hypoid rear axles, Limited -slip or wet clutch applications.



T-5 .....Dexron III / Mercon, Mercon V use.....ATF.......
BUT....(except T-5 from 1985 to 1991 use GL4 Gear Lube)




Another supplier of GL4 found by another CJ Forum Member,
http://www.smittysinc.net/GearOil-GL4.htm
800.256.7575
 
I know this is a really old thread but I was having the same issue as the OP, found this thread and it helped me resolve my leaking T-18 so I thought an update would be helpful to others.

I changed the fluid to the GL4 fluid the MN CJ7 recommended in the above post. That made an immediate improvement in shifting and got rid of the rattle that I was experiencing when decelerating. The Transmission was also going into gear much easier from a stop. I was amazed at the difference the Gl4 fluid made over the standard GL5.

After my first test drive after changing the fluid, I was disappointed because I still had a leak coming from the Transmission shifter. After staring at it for a while I noticed the leak was coming from the threads of the shifter body where the shifter cap screws on. I noticed there were exposed threads and it looked like the cap was not on all the way. I was not able to tighten it anymore so I took it off thinking there may be a seal or o ring missing. That's when I noticed the threads on the shifter cap were full of sludge. So I cleaned the threads and then I was able to tighten down the shifter cap completely on to the Transmission shifter body. A test drive confirmed no more leaking from the shifter.
 

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