T98 Help

I don't have any Ford nor Borg Warner part numbers.
You can get one from an old Ford T98 or possibly this one on eBay is it...

T98-16N MAIN DRIVE GEAR | eBay

Looks like it needs a pilot bushing with large ID.
Ask seller about the OAL and the pilot bore index diameter to be sure it matches your transmission mainshaft gear.
I expect its right near 6-1/2 stick out plus 2-5/8" or 9-1/8" OAL
You need one with 17 drive teeth for T98 only and not for a T18.

 

FYI if you go with the Ford MDG then know that it will be barely long enough; having 3/8" into the crankshaft bushing or less.
May need to use an extended crankshaft bushing.
Also the Jeep T98 bearing retainer will not work with the Ford MDG.
The Jeep T98 bearing retainer was designed to be used as an index into the adapter plate.
Also the fat Ford MDG will not fit into the smaller diameter Jeep T98 bearing retainer.

 

Can confirm. They shortened/re-splined my T18 input 20 years ago with no problems through really hard abuse.

 

Looks like the best bet would be to turn it down. Are the front bearing retainer typically bolted to case or adaptor?
Thanks again
Jay

 

Bearing retainers are always bolted to the transmission.
Foremost they position the front bearing to the transmission.
Secondly they align the bell to the transmission.
Thirdly they provide a surface for the clutch release bearing carrier to slide on.

The Jeep T98 retainer is overly long surrounding the bearing because it was designed to go through a Jeep T98 bellhousing adapter plate.
You likely will need to change to a shorter bearing retainer if you plan to eliminate that front T98 adapter plate.

All common T18 bearing adapters will fit a T98 case just fine.
But GM, FORD and JEEP bellhousing index bores vary.
So you will need to find or modify in order to match the bearing retainer outside diameter to the bellhousing index bore.

Also the bearing adapter snout must be proper inside diameter to match MDG diameter.
The "snout" length needs to be the same as standard for your particular engine.

If you use a T18 retainer (standard or modified) then realize they have a seal instead of inside spiral grooves of T98 retainer in order to keep the gear oil in check.
In addition to shortening; a custom MDG may need to be shouldered to provide a "face" for the gear oil seal.

Got all that ?

 

I wonder ... if it has a GM adapter, why not use it as-is? A T-98 would be a fine transmission if you wanted a truck 4-speed. If the lengthg is not prohibitive ...

 

My concern is the length, would love to loose the 2+ inches of the adaptor.

 

My only experience with adapters was on a t90j to sbc. It had a alum piece that bolt to tranny and acted as retainer then the Chevy retainer bolt to the aluminum adaptor.

 

OK I'll try and make this painless as possible Ha Ha Ha !
What specific engine you bolting this to ?
Were you planning to rebuild the T98 before installing it ?
If you take the T98 apart the 1st thing I suggest is to measure the pilot bore I.D. of the MDG.
I say that because I forgot the specific size of them even though I expect all T98's to have the same mainshaft pilot bore.
That way we can see exactly what other MDG's are feasible.
I'm just wondering that because it may be much more practical to use a MDG from a T18 if by slim chance it fits.
Due to rarity your existing T98 adapter plate, MDG and bearing retainer would be quite valuable to the right person.

If you come across a wide ratio T18 that may provide an advantage to meet your needs.
Myself I like to use a Jeep T18 mated to a Dauntless with no front adapter plate due to short wheelbased flatty installation.

 

This is going behind a Kubota V22203 with a SBC adaptor on the back of it, basically a SBC. My goal is to keep the rear drive shaft as long as I can. The engine will be move up close to the radiator. That along with a SBc Bellhouse I'm hoping to keep the Dana 18 in stock T90 location.
THanks
Jay

 

I understand that... the standard TC location is best if the engine is not too long.
So just how long is this Kubota with a SBC bell installed ?
Crankshaft pulley to the rear face ?

By the way I measured the pilot bore of a Jeep T18 and it is 1.5" I.D.
I'm sure the Jeep T98 MDG bore has a notably smaller I.D.

 

Well I finally got it home and I think figured out what it is. It looks tp be a Jeep truck input. It has a 2 5/8" aluminum adaptor with a stick out of 6 5/8" and is 10 spline 1.125". The bad news was when I pulled the cover, blue gears and rust!!!
I have one more of these in a hard top CJ5 that may be better. Wish me luck.
Thanks far the help.
Jay