I am putting a tranny together for an upcoming project. It's a T-18 with 6.32 gears from a T-98. The T-18 came with the 4 to 1 first, that is why I am swapping the gears. Almost everything was a direct swap, but the inside of the input shaft, where roller bearings ride, is too small. I have tried to find another input shaft that will work, but I haven't had any luck and kind of doubt there is one. If I can machine the i.d. to the right size, it will work.

The question- Will I be taking the hardness out of the machined part? A machine shop said that it may be too hard to machine with a carbide cutter. Has anyone ever done anything like this?

What I don't want to hear- Just find a different tranny. Its not like Wal-Mart stocks T-18's for $50. So I would like to make this tranny work if possible.

This is just an idea maybe post a pic.... or some dimensions...

but in any event is it possible to use some smaller diameter needles/barels in there ? I've noticed that old stuff has larger barel type rollers and nerwer stuff has thinner and more # . Im assuming it due to better material, machining etc....

good luck

-yag

Find someone with an EDM. It uses an electrode submerged in dielectric fluid to cut the part, and cut metal of any hardness. :eek:

Some versions of the T-18 used a 6.??:1 1st....why not use one of them??

check w/ Moser axles. they can cold cut axles. should be able to help you.

I ran into that same problem. I was using T-98 gears with T-18 input shaft. I ended up getting a T-18 output shaft to go with it. What's this going into? What transfer case is going behind it? Can you use a T-18 input shaft from a 6.32 T-18? It will work with your T-98 cluster gear. The other option is getting a T-98 output shaft to go with it. You are also going to have to get a T-98 third gear to go with it if you go that route.

BTW, the T-98 has a 6.40 1st gear. 1st, rev and the gear that meshes with first/rev on the cluster gear have different tooth counts , but the other gears have the same tooth counts and will mesh. Here's my writup on the differences:

http://www.jeeptech.com/oliver/Modifications/Transmission3.htm

You might be able to modify the output shaft instead to use the T18 bearing. A machine shop with a surface grinder should have no problem. Or a home shop machinist that has a tool-post grinder for his lathe might help you out.

I tried to find a T-18 tranny input but mine has 17 teeth and the others has 27.

I was also considering grinding the main shaft (OUTPUT). I figured that this may be easier. The problem is that the machine shop started grinding on the input already so it is no good now. I can find another like mine though.

The trans is going to a Dana 20 converted to Spicer 18, so the output would have to work with a Willy's input gear for the T-case. Grandpa Jeep, I will read your write up and see what I can do. Thanks!

What are the specs of the input? How long and how many splines? T-18 inputs should be a lot easier to find than T-98 inputs. I just went down to a local transmission shop. They had several sitting on the shelf.

O.K. Grandpa Jeep, I read your write up. It sounds like if I got a different output shaft, the input would work. The only problem is that, unlike your tranny, my 2nd gear ratio is not the same in the T-18 as in my T-98. But it sounds like I could get a different gear that would work.

So far it sounds like I need an output shaft from a Scout T-18, and 2nd gear from the same tranny? Any idea of what year the Scout was? Funny that we are doing almost the exact same thing, except mine will be behind a Toyota 22RE, in a Willy's though.

My input shaft is a 10 spline 1 3/8":eek: I already found a clutch to make it work though. I think the inside dia. is probably the same as the one you had though. Had the bigger rollers. The local shop here had some inputs and one just like mine also. None of the others were what I wanted. This one is almost perfect length for the bellhousing I'm using.

Yeah, you need parts from a 6.32 geared T-18.

Now I'm starting to lose track. The output shaft you have is from a T-18 right? The input shaft you have is from a T-98 right? You also have a complete 4:1 gearset from a T-18 and a 6.4:1 gearset from a T-98 right?

If this is correct, you either need to get an INPUT shaft and a 2nd gear from a 6.32 geared T-18. Or you need to get a T-98 OUTPUT shaft that will work with a D18 or D20.

If you do cut or grind your gears, bear in mind gears are often case hardened and you'll likely remove the hardened outer surface which will need to be re-hardened if you hope to have any life expectancy on the gear in question. There, .02

Originally posted by DemoMike
If you do cut or grind your gears, bear in mind gears are often case hardened and you'll likely remove the hardened outer surface which will need to be re-hardened if you hope to have any life expectancy on the gear in question. There, .02

If you decide to alter the gear ID, you can machine it using a wire or sinker EDM. Either way is cold-machining, and you wouldn't have to worry about affecting the hardness of it.

JSSN: Im not picking on you, but...

If you decide to alter the gear ID, you can machine it using a wire or sinker EDM. Either way is cold-machining, and you wouldn't have to worry about affecting the hardness of it.


If you machine off the hard part of the gear it will no longer be hard. :D IE. case hardened gears ;)

The case hardening was for the outside, meshing part of the gear. What purpose is case-hardening to the ID that is the shaft is pressed into?

Originally posted by JSSN
The case hardening was for the outside, meshing part of the gear. What purpose is case-hardening to the ID that is the shaft is pressed into?

The surface he's talking about in this case isn't pressed on to anything, it rides on a rollers, so it is effectively a bearing race.

Originally posted by JSSN


If you decide to alter the gear ID, you can machine it using a wire or sinker EDM. Either way is cold-machining, and you wouldn't have to worry about affecting the hardness of it.
Wire EDM won't do it, you need a through hole. Sinker would but it would have to be case hardened again.

If it is case hardended it would have to be re-heat treated no matter how you machine it. :flipoff2:

A small tool post grinder like someone said above would be good too. Might take a bit longer than EDM but would most likely be cheaper.

Brook :usa:

cant you just bore it for a caged roller bearing that matches the output shaft?
why use loose rollers?

Originally posted by Grandpa Jeep


The surface he's talking about in this case isn't pressed on to anything, it rides on a rollers, so it is effectively a bearing race.

My bad.... I was thinking of a different gear/shaft configuration.

Thanks for the correction guys:beer: