My transmission when I was whining unusually loud whenever I was in second gear, I also noticed some leakage coming from my transmission. IF YOU EVER HEAR ANY NOISE COMING FROM EITHER THE ENGINE COMPARTMENT OR DRIVETRAIN THAT IS NOT NORMAL, STOP IMMEDIATELY. Figure out what's wrong before you drive on it much further.

Note: unlike my tune-up thread, this one doesn't have as many pictures, my hands were pretty full.

How to: Add more transmission oil to your 5-speed manual transmission.

Difficulty: 2 wrenches out of five. Although this project doesn't require any special skills above operating a wrench, it does require some special equipment.

Grime factor: 2 rags out of five. There is some oil spillage involved, but my hands were clean enough I didn't really need too much hand cleaner.

Completion time: 10~15 minutes. The process itself doesn't take too long, but you have to do some slow pumping, and that chews up time.

Tools and parts needed:
Rags. I used two.
A buddy can come in handy to help you refill your siphon pump.
a level parking spot or a means to level out your vehicle.
anywhere from 1~4 quarts 80W100+ manual transmission oil, depending on whether you are doing a change or fill (I used two, I was in pretty bad condition)
Siphon pump for getting oil into transmission, costs about $5. (Pictured left, sprayer fluid on right is for scale. This is a 1 pint siphon pump)

Means to loosen the transmission nut, I have a modified 3/8" wrench piece, machined down to fit. I will refer to this as "t-fit"

Wrench to fit your t-fit (not pictured).

Skills needed:
Ability to operate wrench
Ability to operate siphon pump

Here is a picture of the bolt you will loosen, I took my jeep to the car wash (user-operated quarter kind) and cleaned off my underbody with some tire cleaner and then the power washer, followed by a rag wiping.

To begin, locate the FILL bolt for your transmission. One will be lower on the transmission and was the first one I found. THIS IS NOT THE ONE YOU WANT. If you loosen this one, it will empty out your transmission fluid. The bolt you are after to fill your transmission is higher up, about 2/3 of the way up the tranny (transmission) and I found mine located right above the tranny support strut, as pictured below.

It should be about an inch in diameter. Use your t-fit wrench on this to loosen it. It is a right hand bolt (righty tighty, lefty loosy), but is pretty tight and can take some muscle to loosen. Because of the way it is molded, your t-fit wrench could pop out, some pressure to the back of the wrench to keep it in place may be necessary. The bolt is about one inch long with a pretty fine thread, but once you have it broken loose, you should be able to loosen it by hand. You may want to keep your t-fit wrench on there to give you some grip, it can get pretty slippery.

Once remove the bolt (go ahead and take it all the way out, but be careful not to lose the washer that is on it.), reach inside the hole you just removed the bolt from. Be careful, the threads here can be sharp, so try not to turn your finger too much. Even though you can't fit your finger in there all the way, you should be able to feel if there is any oil on the parts in there (there should be) and if the oil is anywhere near the top. If you have been hearing any whining, it isn't.

Take the top off your transmission fluid (even though some of them come with that ketchup-style squirt top) and stick your siphon pump in, go ahead and go all the way to the bottom to make sure you pull as much fluid as possible. SLOWLY pull the fluid into the siphon. Pulling slow insures that you won't pull air, or if you pull air you won't pull as much. Once your pump is about an inch from being fully extended, pull it out of the oil and turn the tube so it is upright. Wipe it off as soon as possible (from the siphon itself towards the end of the tube) to minimize mess. Place the siphon tube into the fill-hole in the transmission. Push the tube in about as far as you can (the goal is to get beyond that inch of threads in there, remember those?) and slowly push the siphon back in, filling up your transmission. Repeat this process until your transmission starts to drip oil down the outside. You may not see it immediately. I didn't notice mine was dripping until some landed on my elbow, after it had already pooled on my support strut. Once it is full, replace the bolt, making sure to wipe any debris off the bolt as possible. As with all bolts and nuts, start the bolt by hand, tightening it as far as possible before using a wrench. The part may be slick, wiping everything off as much as possible helps. Tighten this bolt about as far as you can go, should be about 40 ft-lbs of force (or about as tight as you can go).

Congratulations! You have successfully added transmission fluid. Give everything a good look over to make sure that all of the parts have been put back in place. Go ahead and start it up and drive around a bit, noting any noises. If you are still hearing unusual noises, have someone who knows what they are doing (preferably a certified mechanic) take a look at your transmission.

 

I just stumbled upon this forum in hopes of some answer in how to fill my 5 speed manual tranny. Will the plug be in the same spot on my 97?

 

Should be, You wont be able to miss it.

 

Hi I am about to change the fluid in my 97 5 speed. Would I just drain the tranny first uing the lower plug. Also maybe someone can give me advice.... My jeep after driving for like a half hour when its hot outside the gearbox gets harder to shift into gears. Especially first and sometimes second. Does anyone think changing the fluid will help? And if I change the fluid the 80W 100+ manual transmission oil works for the a '97 right?

 

My advice on tranny fluid for a Aisin AX15 would be to go to a Mopar dealership and get their 75w-90 GL3 lube. Its the perfect lube, with lower levels of Sulphur/Phospherous that wont harm the syncros as much as newer GL5 lubes. Redline MT90 is also a good choice. These Japanese, brass syncronizer built transmissions Do Not like high levels of Sulphur/Phospherous. Under extreme pressure(i.e. EP additives) the sulphur/phospherous combo adheres to the brass and actually takes off microscopic flakes of brass with it resulting in premature failure of the syncronizers. Sulphur/Phospherous is great for hardended steel gears. Thats what its meant for. Not Brass.

 

Thanks for the help! I checked my owner's manual and it says the same grade you told me.... Maybe I should have checked there first. Anyway thanks for the help

 

FYI people shouldnt give information if they dont know what they are talking about!(Barlow).... My 97 cherokee must be different than the pics posted of an older Cherokee because the drain and fill plug were both 15/16 inch!..... The bolt that was talked about contains a spring and ball bearing behind it! So for anyone unsure with a 97 Cherokee the drain plug is on the bottom of the passenger side of the tranny and the fill plug is 2/3 the way up on the drivers side. They are both big bolt heads (15/16 of an inch) and easily spotted. I drained a little over 3 quarts out and put in about 3 and a half quarts. Thanks for the help from those who know what they are talking about.

 

I just found this thread out of desperation. I am the world's worst mechanic and so I found this easy to understand.

My 1987 XJ is also making a terrible noise-- and unfortunately my wife has been driving it while making a really loud noise in first and second- and only told me about it when it was having trouble shifting into 4th.

Going to try to add fluid tomorrow and see if that helps.

How do I tell which transmission I have. I figure my other alternative is to buy a salvaged tranny from a yard (how much is that?) and try to replace it.

 

Just doing this now. Only probles is mine's a right-hand drive with a diesel motor, so I had to translate - Driver's side = Passenger Side and vice versa. Also, tranny has the 15/16" plugs. I'm also adding 125 ml of Nulon(R) Manual transmission treatment as a precaution against later having low fluid level.

BTW, it's my first Jeep.

 

What fluid did you fill with? Almost all of those tranny additives are targeted at automatics. I haven't seen any positive results in my AX-15 except when I went with Redline MT-90.

Also, since this thread was bumped to the top, I might as well add this: I followed a tip from JeepForum where the author refills an AX-15 in a YJ. He actually removed the shifter handle to pour the fluid in from the top. I've taken this route in my 1999 because I didn't feel like buying a pump. If your tranny has been neglected, this is a great way to clean out the crap that builds up in the shift tower (which is a LOT). Beware it does take a long time to rip the center console out.

 

Bog standard Valvoline 85W/140 gear oil.

The Nulon additive is specifically for manual trannies. Warns on the pack that it is NOT suitable for autos (they make a different one for that).

What it does is deposit a microscopic layer of Teflon on all moving parts, actually only around one molecule thick. The layer penetrates into the surface of the metal. I've used it in every manual box I've ever had, always makes it work better. Heck, I even used one of their treatments in my old motorcycle, it actually made the wet clutch work better.

They make various other treatments to engines too, all working on the same principle. Closest you come to it in the USA used to be Slick 50, although that used a different material and wasn't as effective. I strongly recommend it where it is available. It will be going in my diffs when I do them too.

 

Ahhh...
A few things.

Bog standard gear oil will destroy your synchronizers. API GL-5 rated oil uses a high amount of sulphurous Extreme Pressure additives that is corrosive to the brass synchronizer rings in AX-15s. You need to find API GL-3 or 4, a gear oil that achieves GL-5 without the use of suplphur additives, or a purpose-made fluid for synchronized manual transmissions such as Royal Purple Synchromax or Redline MT-90. Leaving GL-5 in there will cut the life of your transmission in half versus regular fluid.

85w140 is too thick for the AX-15. You will notice reduced fuel economy and poor shifting, possibly increased wear when the transmission is cold. 85w140 GL-5 is designed for hypoid-gear differentials and is not appropriate for use in gear boxes that rely on the fluid being thin enough to splash around. The AX-15 has no pump and can only be warmed up with use. The manufacturer calls for 75w90 only.

PTFE additives for driveline components have fabulous marketing but are 100% a complete scam. DuPont, the manufacturer of PTFE and trademark holder of Teflon, revoked the license to the Teflon name some years ago because the additive absolutely does not work. The US FTC has sued manufacturers of the products for the same reason (DuraLube and Slick 50). Some tests even showed that, in an engine oil application, use of PTFE-containing "anti-wear" additives actually caused an INCREASE in component wear. Complete waste of money.

Seems to me you have some work to do if you want to keep your transmission...

 

Put slick-50 in a 72 skylark 350 SB

80k
Threw a rod in under 2000 miles.

 

Strange. I've put Nulon in every motor I've ever had, ranging from a 1.3 litre Ford Escort through to the 245 Hemi 6 in my Valiants. Never a problem, and they all just kept on going, even after the point where they would normally have needed a rebore. Only ever needed a light hone and new rings. The oil I've got is rated API GL5, BTW. Thicker oil is needed here, where outside air temps can easily top 40 Celsius (104 F in the old scale). I habitually double shuffle my shifts, both up and down, so the syncro rings get an easy time of it anyhow. The Nulon will help there too.

BTW, Slick 50 was never anything like Nulon, it used tetraflouroethylene (TFE), not polytetrafluoroethylene (PTFE). Since only PTFE can be called Teflon, you'll find that that is why Slick 50 and others were sued - they were using the trademarked name on the wrong product.

 

Strange. I've put Nulon in every motor I've ever had, ranging from a 1.3 litre Ford Escort through to the 245 Hemi 6 in my Valiants. Never a problem, and they all just kept on going, even after the point where they would normally have needed a rebore. Only ever needed a light hone and new rings. The oil I've got is rated API GL5, BTW. Thicker oil is needed here, where outside air temps can easily top 40 Celsius (104 F in the old scale). I habitually double shuffle my shifts, both up and down, so the syncro rings get an easy time of it anyhow. The Nulon will help there too.

BTW, Slick 50 was never anything like Nulon, it used tetraflouroethylene (TFE), not polytetrafluoroethylene (PTFE). Since only PTFE can be called Teflon, you'll find that that is why Slick 50 and others were sued - they were using the trademarked name on the wrong product.