3spd noise in 3rd gear

[ftwflh]

My Jeep started making a sound in 3rd like marbles.Got home checked oil it was low.Going to fill with the hope of it helping the noise.If that dont help what are my choices of a 4spd that will work with my Transfer Case ?

 

[BusaDave9]

Marbles. That's not good. Add some oil but bad Transmission bearings sound like marbles. The gears will then have slop and move around too much causing that noise.
I hope I am wrong but this might be a good time to get a T-18 . An excellent tranny. A lot of jeepers will put a Ford T-18 into a CJ (I did) but in your case you need a Jeep T-18 . They will mate right up to your Dana 20 . The only issue is you most likely would need the drive shaft lengths modified.
If you had a Dana 300 then I would recommend a Ford T-18 but that would take a kit from Advance Adapters or Novak.

 

[ftwflh]

What yrs and models of Jeeps had the T-18

 

[BusaDave9]

What yrs and models of Jeeps had the T-18

If you can find a T-18 from a CJ it would be the easiest swap. They stopped putting them in in '80. There were a lot of T18s in other jeeps too but many of the full sized jeeps had a long input shaft.

The T-18 in the top of this picture has a factory adapter between the tranny and the bellhousing. If you get one of these you will have to replace the input shaft with a short one. You can get one from PartsMike® Online

 

[JR74CJ5]

The T-18 Busa suggesting is definitely the top choice if you are desiring a swap to a 4 speed with the low ratio, and are wanting to do the least amount of adaption necessary.

I would venture to guess based on personal experience, it is quite possibly what Busa suggested was the cause as well... The input shaft bearing is most likely the culprit. I had mine go out, (was out actually when i bought it...) and after driving it for a while after the fact, more problems were caused by it.

For me though, 1st and second gear were the noisy ones, and 3rd would quiet it up a bit. Would not completely dis-appear, but would be a lot quieter. When I finally removed it, and had it rebuilt, the input shaft had been damaged, the pilot bushing was toast, the gears were ok inside...

Since you will have, I assume, a lot to do while you have it out, I 2nd this would be a great time for a swap, I still wish I would have done this myself, but was not in the position to do so...

 

[ftwflh]

I am looking for one to swap.If I dont find one in a couple weeks I will pull my 3spd and see what the problem is and try to fix it.Really would like the low 1st.I do a lot of sand and the lower gear would help in not having to use low range on the T case.

 

[Saddle Tramp]

The CJ T-18 was a factory option for 1976 and your bell housing may be drilled for both the Ford “butterfly” T-150 tranny bolt pattern (same a the Ford T-18 ) and the CJ T-18 . I know 1977 to 1979 bell housings were but not sure with the 1976 model year. Jeep used T18s as an option in CJs starting in 1972 and ending in 1979, but up until sometime in 1976 the 1st gear was a 4.02 ratio. Sometime in 1976, exactly when is a bit of a mystery, the change was made to the more coveted 6.32 low.

There are a few other fine points too. One is that a round Dana 300 adaptor on the back of a T-18 will make the rear drive line too short for a CJ5 . In a CJ7 it will work due to the extra length of the 7 but the only way to put a Dana 300 in a 5 behind a T-18 is to find a 1980 Scout Dana 300 that originally lived behind a T-18 /19 as it has the same “Texas” bolt pattern of the Dana 20 you currently have; they are rare and hard to find. Take a look at these:

http://www.jeeptech.com/convtrans/cjt18/

http://www.jeeptech.com/convtrans/fordt18/index.html

 

[ftwflh]

Got a qt in and drove it 5-6 miles in 3rd and no noise.Still like the idea of a 4spd

 

[BusaDave9]

Do NOT get a Ford T-18 . They would not mate easily to your Dana 20 .
Get a Jeep CJ T-18 and it will be a very easy bolt-in swap. The only issue will be to have the drive shaft lengths modified. The T-18 is longer.

If you had a Dana 300 I would recommend a Ford T-18 .
I once had a CJ7 that I swapped a Ford T-18 into. But I had a Dana 300 . BIG difference. I had to get an adapter from Advanced Adapters (Novak also would have worked). I replace the T-18 main (output) shaft. I also had to drill and tap 4 holes in the bellhousing.
A ford T-18 would require that you get an adapter to mate to your Dana 20 TCase.

 

[Saddle Tramp]

Which T-18 you buy, Jeep or Ford, probably will have a lot to do with what you can find. I seem to see more CJ T18s available lately, most likely due to the fact CJs are being parted out in greater numbers now than in years past as time and rust takes its toll. However CJ T18s still aren’t prevalent enough that prices aren’t pretty high, $900-$1,100 or so where I live. The Ford version is readily available in comparison; I saw one on Craig’s List the other day for $225. At that price by the time you buy the needed special pilot bushing and the rear adaptor/shaft kit even with a professional rebuild the total investment at worst shouldn’t exceed the cost of a rebuilt CJ T-18 . Granted the CJ version is sweet as the Transfer Case adaptor is part of the Transmission right out of the box and no special parts or adaptors are required but sometimes availability of product and/or the number of pennies you need to shake out of the piggy comes into play too.

 

[ftwflh]

Decided to just get a spare T-150 and Dana 20 that is in good condition.
Easy swap out and only $100 for both.