Tranny Swap Advice

I am having problems with the tranny on my recently purchased 73 CJ5. Many of you have seen the pictures and my recent questions. I figured out that I currently have the T14 tranny and the engine is a Chevy V8. The tranny constantly slips out of first gear or won't go into first gear. The shop doing my other work is telling me they have to open it up and take a look to tell me what it will cost to fix it. The diagnostic is going to be 4 to 6 hours of labor charges and the repair can be anywhere from $200 to over $1000. I asked him what it would be to put in a new tranny if I provided the tranny. He told me it would be just 4 to 6 hours of labor. So, I have a few options.

1. Buy a rebuilt T14 for $995 and have it installed for about $300.

2. Pay $300 in labor for diagnostics and hope it is a cheap repair that is needed.

3. Upgrade to a tranny that better matches the stroked performance engine.

My question to you guys is what transmission options do I have. Is the T18 a better tranny? I like the idea of 4 speeds. Would it or any other tranny be a direct swap or would it require a lot of work that would put me over the 4 to 6 hour labor estimate? I would like to just do an upgrade now, but not if it is going to increase the complexity of the install and cost a lot more.

Do any automatic trannys fit?

Thanks in advance.

 

The T18 is stronger than the T14. It won't just bolt up though. Go here to get more info.

http://www.novak-adapt.com/index.htm

 

Upgrade, an SM420 or SM465 would be good choices behind your chevy V-8.

 

This would be a great time to swap your tranny! Like mb82 suggests, the sm420 or sm465 will give you a really low granny gear, and from what I have learned from reading in this forum, those are two of the best
manual tranny's you could put in your jeep. Check out novak-adapt.com
and click on the knowledge base tab and see what you think. I think you might be able to adapt a sm 420 or 465 pretty easily. Good luck, and let us know what you decide.

 

My vote is for the SM465 with your stock Dana 20 mated with a Novak 1" adapter.

 

Shoot, don't spend more than parts money on a T-14, esp. behind a SBC.

R&R for a transmission in a Jeep is pretty easy - you don't want to do it yourself?

Contact Herm the Overdrive Guy and ask him for a quote on a bench rebuild of your transmission.

If you have a T-14, it was only used behind the inline 6s. The '73 with a V8 would have had a T-15, which is a stronger transmission. The T-150 is prefered over the T-14. The T-14 has a slightly lower 1st ratio than either the T-15 or T-150, but the ratio spacing 2-3 is much better on either. You'll have a usable passing gear. A swap to a T-15 would be a big improvement.

You realize that the T-18 is a wide ratio truck transmission, with a 6.32:1 "granny" 1st gear? In a CJ, you'd never use this gear on the street, instead starting in 2nd. All the 4-speed truck transmissions (T-18, NP435, SM420, SM465 etc) are huge compared to the 3-speeds, and much stronger.

You can also use a 4-speed car transmission, of the sort that you would have in a 60s muscle car. These aren't as popular today as as the truck transmissions, but many are strong and will stand up to your engine. Close ratios typically; best suited to the dunes and hill climbing, not rock crawling.

The GM TH350 will fit, but your rear driveshaft will be short. The CJ-5 was never offered with an automatic from the factory because the wheelbase is short and the automatics are long. A TH350 would be fine if it's done right, but it's a more ambitious project than the manuals. More than a couple of inches of lift could be a problem, due to the increased angularity of the (short!) rear driveshaft.

 

Whatever TIMGR says.
He word is law here and he is always correct.

Oh man, was I being nice. No more being nice, must fight this...

 

All have covered it pretty darn well. Would like to add a little here though. Pretty much whatever trans you swap to except the T-15 or T-150 will require drive shaft modifications which means more money. The T-18 is a a great tranny and if you don't want the 6.32-1 low gear they can be built with a 4.02-1 first for a more even shift. First is still non-synchronised.
R&P sells T-18's that have been modified to bolt directly to GM bellhousing with NO adapters and are adapted to either a 20, 18, or 300 transfer case depending on choice.
The SM-465 or SM-420 are both good choices. Most car tranny's unless a top shift like your tranny will require cutting the tub for the shift linkage and most have a lousy first gear for a Jeep, but are do-able.
I feel for any V-8 the T-14 just isn't strong enough. Guys with stock V-6's are breaking them when off road. The T-15 would be a fairly simple upgrade and would be much stronger. Herm and R&P could both supply you with what you need. Nickmil

 

Thanks for the compliment, I think :?

Any new transmission is going to involve conversion "issues" like changing the transmission mount, modifying the crossmember, shortening the driveshafts, or even realigning the rear axle to address driveshaft angularity.

A T-15 from a 72-75 CJ would not need an adapter, but the T-15 is slightly longer than the T-14 so you may need to adjust your driveshaft lengths. It should go in with only stock parts and no changes to the floor.

All these others will need an adapter for the transfer case end, and you'll need to change the floors, driveshaft, mount, etc.

If you're going to have it done, I'd recommend that you find someplace with experience swapping transmissions in Jeeps. Call Scotty's and ask them if they'd do it.

 

I think the "H" in your VIN means 304, so you may already have a T-15. It does in a '72 VIN, and I think it's the same in '73. Who told you you have a T-14?

 

Herm's website quotes $300.00 for a rebuilt T-14 with no exchange.

 

I told myself. I looked at it and then pictures and model year info from jeeptech.com and made a guess. I asked the mechanic to take a better look and confirm it for me, but he is working on the brake issues and starter first.

 

Not doubting you, but the T-14 and T-15 look the same unless you have them side by side. The only reliable way to tell them apart is by the ID tag under one of the top cover bolts (often lost), or the 1302 or 1307 cast into the side of the case for T-14 or T-15 resp.

 

Oh no. You can doubt me. I do it all the time when it comes to this stuff. I am great at electrical and aftermarket, but the engine and tranny are latin to me.

 

Timgr, you are right, I did a little research and the the ' H ' in the VIN of my '73' CJ5 represents the 304 CID engine. Mine has the t-15 tranny.
Hope this helps.

 

If you have a t-15 i'd suggest re-building it yourself. I had a leak in mine and ran it without gear oil for quite some time. Melted a couple syncros I was able to rebuild mine with a good FSM, zero trans knowledge and a large work table to lay the pieces out in order. Very simple to work on.