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Just got a 1979 CJ5 with an in-line 6 and a 4-speed Transmission . When I disengage the clutch while in 4th gear (faster than 35-40mph) there is a loud grinding sound. It sounds like I'm shifting and grinding the gears, but constant. The only way I've found to stop the grinding is by re-engaging the clutch and giving it some gas, or by slowing down to less than 30mph. Shifting into 3rd is difficult and doesn't stop the grinding.
Is the throwout bearing shot, or is it something else?
No matter what, with a new unfamiliar CJ you should change the Transmission and Transfer Case oil. Be aware that if you have the stock Transmission /Transfer Case they might very well share their fluids. I know the T-15 /Dana 20 and T-14 /Dana 20 & D18"s shared there fluids. Since it's winter don't use the truly heavy oil/gear greases.
'85 CJ-7, 258/4.2L 6cyl. Bought new in 1985. Full cage, Warn 8274 winch, Ford 9" rear, front/rear Detroit Lockers w/4:88 R&P. T-5 tranny and 4:1 t'case. 33X12.50-15 BFG/AT, MSD ign, on board air---
Thanks guys. I'm a brand new Jeep owner, so I'm still learning the basics. So after some research, I found out that I have a T-18 and a Dana 20Transfer Case .
My next question is what oil(s) I should use for the tranny and the Transfer Case ? Do they share fluids?
If any of you has a DIY tutorial on changing the fluids on these, that would also save me a massive amount of time.
'85 CJ-7, 258/4.2L 6cyl. Bought new in 1985. Full cage, Warn 8274 winch, Ford 9" rear, front/rear Detroit Lockers w/4:88 R&P. T-5 tranny and 4:1 t'case. 33X12.50-15 BFG/AT, MSD ign, on board air---
Use 80W-90 API-GL5 rated gear oil.
They are not supposed to share oil, make sure your vents are working.
Might be time to change to oil in both diffs also.
Use same oil........
Use 80W-90 API-GL5 rated gear oil.
They are not supposed to share oil, make sure your vents are working.
Might be time to change to oil in both diffs also.
Use same oil........
Alright, Some earlier transmissions do share Transmission /Transfer Case oil. Your T-18 does not share with the Transfer Case so that is not a problem. I know I brought up the possibility so forget that.
Changing or servicing Transmission oil/grease is simple but a dirty proposition. You need to crawl under the CJ and look/feel around. On the Transmission you will find two square headed drain plugs on the passenger side. One toward the bottom and one toward the top. Obviously the top is for filling, the bottom for draining.
The Transfer Case has a big pan on the bottom with a plug in it. I've seen them with the same square outie type plug or with an innie type plug. The innie plugs take a 1/2" socket drive handle, you will probably need an extension to get to it. That is the drain plug. You will find a corresponding fill plug above the drain on the back of the case.
Simply drain the case in an environmentally responsible manner, replace the drain plug and using the type Transmission oil Liumpy suggested using the upper/fill plug hole to fill the case until oil/grease starts dribbling out. Replace the plug and you are done.
The upper fill holes are famously difficult to get to for filling. Most here use one or the other version of an oil pump designed to attach to an oil container to pump oil into the cases. These pumps are available at most any automotive store. Get one to fit the container you are using and have at it.
With all that being said, if it were me I'd try filling your Transmission first and see if your noise goes away. If it does, go ahead and sacrifice the new oil you just put in and change your fluids. If you can do it while right after driving the vehicle while the oil is still hot.
There are a couple much more serious things you could do. The T-18 has an inspection cover on the lower drivers side. You could pull it and inspect your gears. But mostly, there is a magnet glued to the inside bottom of our case near the inspection cover. It's there to catch metal shavings and such. Guaranteed it will be a lump of greasy metal and goo from running for
+35 years. Scrape off the metal and goo to inspect the debris. Small shavings and such are normal wear, BIG chunks are not. Also be aware, the big bottom gears will be chipped some, that is normal with an unsynchronized first gear. Which has me thinking, you know that the '79 T-18 's first gear is not intended to be used in normal street use. It is a compound or more commonly called a granny gear used when raw slow speed power is needed. Your T-18 is made to start moving in 2nd gear.
You have one of the most desirable CJ transmissions ever put on a jeep. They are rock solid tough, made to take abuse and keep on going.
1979 Jeep CJ7 TH400 Automatic 258 I6 Quadratrac Amc 20 rear & Dana 30 front, 32 x 11.5 x 15 tires. Currently a Complete Custom Rebuild in progress.
Also I own a 2001 Jeep Cherokee, White, all stock with 4.0L. automatic, and police package. Best part of that is it came with leather seats! This package also has the NP242 Transfer Case, 8.25 rear end, and trailer towing package.
Vent tubes. You'll find thee on the axles, Transmission , and Transfer Case . Look around for hopefully a rubber hose usually pretty small that goes up and away fro these components. If you don't find that, look for a hole near the top. If all you have is a hole, you'll need to add a hose to it to get the vent up and away from water.
Alright, Some earlier transmissions do share Transmission /Transfer Case oil. Your T-18 does not share with the Transfer Case so that is not a problem. I know I brought up the possibility so forget that.
Changing or servicing Transmission oil/grease is simple but a dirty proposition. You need to crawl under the CJ and look/feel around. On the Transmission you will find two square headed drain plugs on the passenger side. One toward the bottom and one toward the top. Obviously the top is for filling, the bottom for draining.
The Transfer Case has a big pan on the bottom with a plug in it. I've seen them with the same square outie type plug or with an innie type plug. The innie plugs take a 1/2" socket drive handle, you will probably need an extension to get to it. That is the drain plug. You will find a corresponding fill plug above the drain on the back of the case.
Simply drain the case in an environmentally responsible manner, replace the drain plug and using the type Transmission oil Liumpy suggested using the upper/fill plug hole to fill the case until oil/grease starts dribbling out. Replace the plug and you are done.
The upper fill holes are famously difficult to get to for filling. Most here use one or the other version of an oil pump designed to attach to an oil container to pump oil into the cases. These pumps are available at most any automotive store. Get one to fit the container you are using and have at it.
With all that being said, if it were me I'd try filling your Transmission first and see if your noise goes away. If it does, go ahead and sacrifice the new oil you just put in and change your fluids. If you can do it while right after driving the vehicle while the oil is still hot.
There are a couple much more serious things you could do. The T-18 has an inspection cover on the lower drivers side. You could pull it and inspect your gears. But mostly, there is a magnet glued to the inside bottom of our case near the inspection cover. It's there to catch metal shavings and such. Guaranteed it will be a lump of greasy metal and goo from running for
+35 years. Scrape off the metal and goo to inspect the debris. Small shavings and such are normal wear, BIG chunks are not. Also be aware, the big bottom gears will be chipped some, that is normal with an unsynchronized first gear. Which has me thinking, you know that the '79 T-18 's first gear is not intended to be used in normal street use. It is a compound or more commonly called a granny gear used when raw slow speed power is needed. Your T-18 is made to start moving in 2nd gear.
You have one of the most desirable CJ transmissions ever put on a jeep. They are rock solid tough, made to take abuse and keep on going.
Vent tubes. You'll find thee on the axles, Transmission , and Transfer Case . Look around for hopefully a rubber hose usually pretty small that goes up and away fro these components. If you don't find that, look for a hole near the top. If all you have is a hole, you'll need to add a hose to it to get the vent up and away from water.
'85 CJ-7, 258/4.2L 6cyl. Bought new in 1985. Full cage, Warn 8274 winch, Ford 9" rear, front/rear Detroit Lockers w/4:88 R&P. T-5 tranny and 4:1 t'case. 33X12.50-15 BFG/AT, MSD ign, on board air---
I urge you to start keep'n a log of all/any work done.
Include mileage, date and any PN's for parts/filters, and oil weight used.
Keep the parts receipts in a folder.
GOOGLE is also a great source of info for our Jeeps.
I also urge you to get a copy of the REAL factory service manual(FSM). 1979 Jeep Service Manual (Body/Chassis) ? CBJeep
I urge you to start keep'n a log of all/any work done.
Include mileage, date and any PN's for parts/filters, and oil weight used.
Keep the parts receipts in a folder.
GOOGLE is also a great source of info for our Jeeps.
I also urge you to get a copy of the REAL factory service manual(FSM). 1979 Jeep Service Manual (Body/Chassis) ? CBJeep
'85 CJ-7, 258/4.2L 6cyl. Bought new in 1985. Full cage, Warn 8274 winch, Ford 9" rear, front/rear Detroit Lockers w/4:88 R&P. T-5 tranny and 4:1 t'case. 33X12.50-15 BFG/AT, MSD ign, on board air---
'85 CJ-7, 258/4.2L 6cyl. Bought new in 1985. Full cage, Warn 8274 winch, Ford 9" rear, front/rear Detroit Lockers w/4:88 R&P. T-5 tranny and 4:1 t'case. 33X12.50-15 BFG/AT, MSD ign, on board air---
Have you ck'd the U-joints for play/slop?
Also, look to be sure you don't have something rubbing like an exhaust pipe.
How does the tranny feel when you shift?
How much freeplay/travel do you have in the clutch pedal? You want 1" to 1 1/4". No more, no less.
LG
Have you ck'd the U-joints for play/slop?
Also, look to be sure you don't have something rubbing like an exhaust pipe.
How does the tranny feel when you shift?
How much freeplay/travel do you have in the clutch pedal? You want 1" to 1 1/4". No more, no less.
LG
Everything appears fine. The gears shift well enough, and I think I'm well within the limits of clutch play. The grinding happens when I completely disengage the clutch while going over 40 (in 4th gear), or completely let off the gas while going over 40. Giving it a little gas gets rid of the grinding, and the grinding stops on its own once the Jeep slows to about 30mph.
'85 CJ-7, 258/4.2L 6cyl. Bought new in 1985. Full cage, Warn 8274 winch, Ford 9" rear, front/rear Detroit Lockers w/4:88 R&P. T-5 tranny and 4:1 t'case. 33X12.50-15 BFG/AT, MSD ign, on board air---
CK the U-joints and slip spline on your rear drive shaft for play & slop.
Grease'em if you can, many u-joints have zerk fittings, same for the slip spline.
LG
