Transmission Trouble

Hey guys. I have a 73 Cj-5 with the 258 inline 6 with a 4-speed. I started my restoration back in 2004 with the good intentions of replacing the transmission as soon as possible. Well the jeep got totally restored and now I've saved the best for last. I am looking for some help with replacing this transmission. I would really like to put a 5-speed in the jeep but so far I'm having trouble figuring out what fits. Can anyone be of any help?


Thanx

Jason

 

Oh my, why? The 258/T-18 is a very desirable setup.

A good 5-speed transmission will be quite a bit longer than the present 4-speed, and will be difficult to install.

I'd say stick to the transmission you've got - it's a great transmission. Drive it and be proud.

Or else trade for a later CJ with the (weak) T-5 5-speed transmission.

 

Here is a picture of my jeep

 

I have to have a new transmission. This one has given me so much trouble of the years and I'm just done with it. It is geared so low. I rarely use first gear and that is mainly when I am taking off up hill.

 

What kind of trouble? The T-18 is a very strong and reliable transmission. People pay big money for low gearing in a Jeep. Among knowledgeable buyers, that transmission is very desirable. Replacing the T-18 would be a mistake, IMO.

Seriously, if you don't like the shifting of this Jeep, sell it and get a newer version with one of the car transmissions like the T-176 or T-5. Or maybe a Wrangler, which would be much more car-like. If this Jeep does not suit you, get one that does.

This is the close-ratio T-18. Customers that had this transmission really liked it. The ratios are excellent on the trail, and they were particularly good for terrain with a lot of hills and steep descents. The T-18 is a real truck transmission, and shifts like one, but that's the price of its excellent strength and durability. Plus the ratios are great.

 

I've had several jeeps and a couple CJ's. This one has been a 6 year project. I will do my best to never sell this jeep. The body is immaculate. No rust and near flawless. The synchronizers are bad. I've had many problems with the pressure plate. Sometimes you have to double shift. Sometimes in order to get it in first you have to put it in reverse again........

 

The pressure plate has nothing to do with the transmission. Replacing the transmission won't change whatever clutch problems you have.

It will never shift like a passenger car. You may need to go into the other gears to get into 1st, or even spin the input a little to make it go in.

Do you have gear clash when shifting into 2nd, 3rd or 4th? If so, you need to either shift more slowly or replace the blocking rings, or both. The internal parts of these transmissions don't wear much in this application because the transmission was designed for use in a much heavier vehicle than a CJ-5. The penalty for this is that it takes more effort to shift, and you must move between gears more slowly.

Double shifting to get in to 1st is expected, because 1st gear is not synchronized. However, you should not need to double clutch in your day-to-day driving.

You really need a relaxed attitude to be happy with one of these transmissions. They are very strong, but the gears are heavy and will resist if you try to shift too fast.

To me, it's no big deal (except in stop-and-go traffic) - I have driven these transmissions in my cars and as part of my job since I started to drive. Maybe it would be helpful to find somebody else to drive your Jeep that knows these transmissions, so they could see whether this transmission is behaving normally or not.

 

Nice Jeep!

I'd kill for a T-18 in my Jeep. People spend $1500 to convert to T-18's, arguably one of the best transmissions in the '5 (along with the SM420 and SM465).

I don't think there is any 5 speed that will fit.

 

The T-18 is fairly easy to rebuild if you are comfortable with that kind of work, or you could have a shop do it.

You can replace the pressure plate without replacing the transmission. This might solve some of your shifting problems if the clutch disc is not being released completely. Replace the clutch disc at the same time, no sense in pulling the transmission later to change the disc.

I am not sure about double shifting, do you mean double cluthing?

1st and reverse are non-syncro, so shifting from one to the other is necessary sometimes to line up the gears. Just make sure you are stopped when trying to shift into 1st or reverse.

 

Thanks davistroy!

Well I am fully stopped when trying to put it in reverse. For example if I've been driving it and pull in somewhere and try to put it in reverse, 95% of the time it scrapes gears unless I turn it off and place it in reverse before cranking up again. I've had the pressure plate replaced twice. The one in it now is the correct one. The main reason I want a 5-speed is because the T-18 in it now is geared really low. At 55 MPH it is screaming. It's not that I want to go fast I just don't want to turn that many RPMs going under 60 MPH.

Keep the comments/help coming guys. Much appreciated!!!
:monkeys:

 

Hmm. This sounds like a clutch problem to me, not a transmission problem. With the clutch in, the weight of the gears and resistance against the bearings is way more than enough to bring the transmission to a complete stop after a few seconds. The only way the gears can keep spinning is if friction between the pilot tip and the pilot bearing is so high that the pilot bearing turns the input shaft.

If the gears are spinning, then you will hear gear clash when you shift into 1st or R. You may still be able to shift, since the clash forces the gears to stop and mesh, but it's not supposed to work like that.

The pilot bearing is at the center of the engine flywheel. Its only purpose is to support the front end of the transmission input shaft (the pilot tip). The pilot bearing is supposed to be well lubricated and loose.

 

Just my 2 cents...If it was mine I'd check that the clutch was fully disengaging in order to shift into reverse without shutting down. I know that if my clutch pedal is not adjusted correctly, I can't put it into first gear without grinding.
As far as the engine screaming at highway speeds, mine with 4:11 gears turns around 3000 at 60 MPH. Are you sure you're not in 4 low at the transfer case?
I don't own a T18, but I thought most gearboxes were 1:1 in top gear? That would give you the same engine speed as others, not counting for final drive ratio and tire size.
I could be all wet here, but just had these thoughts floating in my head.:?
I also agree with Tim's thoughts as well.

 

Also, how fast is the engine turning, really? The inside of a Jeep is quite noisy, and the engine is fine at those speeds. What axle ratio do you have? What is your tire height?

Worst case, let's say you have 31" tires and the optional 4.27: axle ratio. Then your engine is turning 2776 RPM at 60 mph. This is perfectly fine. I think the "screaming" is mostly your perception, but not an operational issue.

If you want to make the cabin quieter, you can.

 

Yes. Only overdrive transmissions have a different ratio.

 

slipping clutch?

 

LOVE IT!! Especially the OEM wheels! Nice lines. atriot:

 

It's not a five-speed, but check the "Ford RTS" four-speed Overdrive here: http://hermtheoverdriveguy.com/id41.htm

If all you're looking for is an overdrive this will get the job done. You should be able to sell off your existing T-18 setup to recoup probably half of your investment.

 

if you do decide to swap tranys i want to buy your t-18 just name the price i am looking for one to go in my 75 cj-5

 

So after talking with mechanics I'm thinking of just having my T-18 transmission rebuilt. Is it possible to add and overdrive to it?

 

That depends on the transfer case. D-18 yes. D-20 no. Divorced over-drives have been installed.