T5 upgrades

kb426 · February 08, 2021, 11:10:42 AM

Has anybody used any of the supposedly stronger parts to build a t5 and seen if they are a worthwhile purchase?

enjenjo · February 08, 2021, 08:19:43 PM

It depends on what you have in mind for it. The really weak link in a T5 is reverse. Abuse it one time in reverse, and you have eaten the cluster. One thing that helps this is a cluster girdle. They cost about $50 and are worth it. It keeps the rear cluster bearing retainer from bending and letting the back of the cluster drop under load. I recommend a 2.95 first gear set because it is by it's nature stronger than any of the lower first gear set.

If you are planning on drag racing there are also 9310 gear sets with a low helix angle and wider gear that are good for 430 hp, but you are getting into the $2000 and up range for the transmission. And reverse is still the weak link. Of course a good stock rebuild is in the $1200 range with new parts.

I have had two return on the transmissions I build. The first one blew a rear U joint and bent the mainshaft. The second one came back for no 5th gear, a snap-ring broke and allowed the driven gear to move out of mesh.

I would look into Pro Motion for parts, http://promotionpowertrain.com/products.html or even a complete transmission.

kb426 · February 10, 2021, 06:34:40 PM

I appreciate the info. After researching some more, I arrived at the same conclusion I did when building the 32 back in 07. If you have some power and really drive it, you will break it. Rather than buy a tko 500, I'm leaning towards the new tkx. I don't like the price but I sure do like the specs.

jaybee · February 10, 2021, 08:44:34 PM

I've done a fair bit of research on engine-trans combos, and it seems clear time has outrun the T5. If you make significant power by today's standards, unless you're in a lightweight car which won't hook or you're content to baby it they're marginal without spending significant money on upgrades. I haven't built one or raced one so I'm open to being wrong, but to me that seems like a good problem to have.

The Shelby-modded 289 Hi Po claimed 306hp and just about the same for torque. Nowadays with the right cam, heads, intake, and headers you can wring just over 400hp and around 380ft lbs of torque out of a 5.0, mean-sounding but streetable and running on pump gas. Step up to a 347 stroker and you're over 450hp. Good luck putting any hard miles at all on a 351-based stroker.

Of course as with all mechanical things manual transmissions have always been more breakable in the hands of some people than others...even with all other things being equal.

enjenjo · February 10, 2021, 10:44:37 PM

T5s still have their place but it's not behind a performance engine. Most of them I sell are used with flatheads or Chevy sixes. I have sold one that is behind a 390 Caddy, but he doesn't beat on it at all. And of course that one got a bunch of good parts in it.

kb426 · February 11, 2021, 08:01:28 AM

When I bought the t5, I had thought about using it behind the engine from the 88 f150. I had talked about a real light roadster. When the 78 arrived, that put that plan on the back burner. When I pitched the 6 cylinder and installed the 5.0, I lessened the need for the t5. In a couple of months, I will try to sell the 78 again. If it doesn't sell, I will make a decision to either rebuild the c6 I have and install it or the t5 in the 78. I think, not many want the old NP 435 trans to drive around with.

The t5 would make that a real nice driver.

jaybee · February 11, 2021, 07:32:55 PM

Quote from: "enjenjo"T5s still have their place but it's not behind a performance engine. Most of them I sell are used with flatheads or Chevy sixes. I have sold one that is behind a 390 Caddy, but he doesn't beat on it at all. And of course that one got a bunch of good parts in it.

I know a guy in Missouri who's collecting parts for an A coupe. He has a T5 to go behind his flathead, which is a great combination.

enjenjo · February 11, 2021, 08:08:23 PM

Quote from: "jaybee"
Quote from: "enjenjo"T5s still have their place but it's not behind a performance engine. Most of them I sell are used with flatheads or Chevy sixes. I have sold one that is behind a 390 Caddy, but he doesn't beat on it at all. And of course that one got a bunch of good parts in it.

I know a guy in Missouri who's collecting parts for an A coupe. He has a T5 to go behind his flathead, which is a great combination.

I have even built a couple T5s that will bolt up to an early Ford closed driveshaft. I also built one that is hooked to a 31 Chevy closed rear end.

kb426 · February 12, 2021, 07:23:00 PM

If I'm not careful, I will end up rebuilding it and saving it for something.

Pete · March 26, 2021, 05:17:12 PM

Quote from: "kb426"Has anybody used any of the supposedly stronger parts to build a t5 and seen if they are a worthwhile purchase?

Yes, I did. When I needed a T5 I had my transmission guy build me one from parts. And yes it is worth it if you are going to put 400 hp through it. I don't do transmissions so I don't keep up on all of the latest "tweeks".
Some of the stuff he did was, after market high alloy gears, similar to the 212 gear set ratios, some kind of fancy synchros, reverse girdle and 2 bushings in the tail shaft housing for more support on the slip yoke. He also installed a street "L" in the oil fill hole in the side of the case. This raises the oil level inside about 3/4 of an inch. I run ATF for oil.
I made the short throw shifter with stops. That is the neatest part of the whole thing, the knob goes 4 inches from 1 to 2.