Kaploooy.....

Got home from an elk hunt in November/December and the tranny/t-case was leaking furiously. I took her to the shop to have it resealed but the mechanic, who I trust, says I need a rebuild and we are currently looking some other options...

My question...was the 4spd ever an option from the factory with a 304 in '76? I have read extensively on a conversion, which tells me No, but just checking. After this, the only original parts will be the axles.... An additional concern would be if I upgrade to a granny low in the 4spd, will that be too much for my 34yr old AMC20 rear 2piece to handle?

 

The Weak point in the AMC20 is the axle tubes are thin making them easier to bend. As long as you are not hopping around alot you should be good.

 

There were some wide-ratio T-18 4-speeds with CJ 304s, but all sources indicate '77-79 only. In '76 Jeep still used the close ratio (4.02:1 first) T-18 in the CJ (same as from '71-75), and that was only offered with the inline 6s.

Re the axle, it all depends on your driving style. I have no experience with these axles, but others who do say that it will last if you are careful to keep the axle nuts torqued to spec. Certainly the axle will see twice as much stress from a 6:1 transmission ratio as a 3:1 ratio, all other factors equal.

You have the T-150 transmission, which is a decent alternative. A T-150 is a Ford transmission, and should be easy and inexpensive to rebuild. You could add the 3:1 gears to your transfer case and gain 50% more reduction over the factory Dana 20, and the extra labor if you have the transfer case apart is not much.

If you are thinking that the factory option would be a bolt-in for your T-150, well, it depends on your definitions. If you had a donor car and take all the pieces you needed, then it would be straightforward. The '77-79 CJ T-18 would work like this, but I think the word is out about these, and what few 304 versions are out there are sought after. An inline 6 donor would work pretty well, but I expect the driveshafts (and thus the trans location in the chassis) are different - I'd have to look it up.

Personally I think you would be better off to find a Ford pickup T-18 or NP435 and buy a conversion kit. There would be some issues to sort out, but you could do that now without combing the country for a suitable donor vehicle. The Ford transmissions bolt up to the T-150 bell; you'd have to figure out the clutch linkage, trans mount, transfer case shifter location, and driveshafts, but it's straightforward, at least as these projects go.

hth!

 

Thanks, guys!

 

The trouble with two piece axles is that they have castle nuts. people have the habit of torque to down and when the pin holes don't line line up. they turn them back! you are to turn tighter and put the pin in. the book say 150 ft pound min and 250 max

 

Alright, found a donor T-18. The T-150 is going to run $1500 to completely rebuild w/ the transfer case. I can get the donor for MUCH cheaper with only a few mods on the front and rear drive shafts as well as a slight extension on the transfer stick. For the most part, the T-18 will bolt right into the T-150 housing. Still working on it....

 

A T-18 from ... what? Only the Ford T-18 will bolt up to the T-150 bell, and you'll need an expensive conversion kit (ca $600) to adapt it to your transfer case. To install the conversion, you have to take the T-18 completely apart.

Call Herm, and ask how much a rebuilt T-150 would cost exchange. www.hermtheoverdriveguy.com

 

$1500 is way too much. R&P sells a ready to go already adapted T-18 to fit your application for around $995 with mount and pilot bushing as a comparison.

 

I am going to use a T18 with the granny first. The CJ T18 and T150 bellhousing are very close. You need to drill and tap one hole. I talked to Mike at PartsMike.coma nd I think the parts I needed, other than a new clutch, ran less than 20 bucks....

 

My research reveiled that 250lbs was incorect from the factory. Police cars were made with the 20 (wider of course) and that manual says 450 lbs. I torqued mine to that spec and NO issues...