airbum

What is everybody using for a 1 gear/5 gear ratio? I just got Martins book and he recommends 2.95 1st and .63 5th. Other than a reman trans I can't find any salvage trans with these ratio's?

Thanks!
Rusty

Al English

2.95 is the highest first gear available in a non-aftermarket T-5. Depending on the axle ratio you use, even the 2.95 may be a little lower than ideal. Definitely avoid the even lower first that's in other T-5s. The 2.95 first "Z" spec T-5 was used in some Mustangs. I don't believe it was used in anything else. They aren't everywhere, but can be found. On the plus side, it is also the strongest of production T-5s. Not cheap, but you can buy that trans new. If you spend even more, G-Force offers even higher first gear ratios, and options that make the T-5 even stronger than the "Z" series T-5.

Gunpilot

I found a place on the Internet that specializes in these transmissions. They sent me a rebuilt unit with brand new gear set with the gear ratio recommended in Martain's handbook. It was under $1000 shipped. Ill post company name when I look at receipt at my shop.

airbum

Al
Thanks for the input. Now how do I tell a "Z" spec t5? Sorry for being so dum to all this Ford stuff. I am a old school chevy guy.

Thanks
Rusty

airbum

Gunpilot
I called APM, thats who Martin recommended, they quoted $1695 delivered. Everything is going up!

Thanks
Rusty

Al English

If you shop around you can find a new T-5Z for $1,500 or less.

MRM331

Napa, Summit, Jegs

The most cost effective solution I've found is a custom built one. Search the site, there is a link here somewhere for someone who will build you one to your spec for under $1000.

-Jason

airbum

Al
Thanks, been looking and am down to $1295

Rusty

airbum

Jason,

I have been looking at gear sets to do a convert. I am a retired ASE master collision repair technician /vocational instructor, that did alot of hot rodding in the 60's and 70's. I have experience with saginaw's and muncie's of days gone by, so i may try this myself.

Thanks!

Rusty

charchri4

Hey $1295 is a lot cheaper then a T56!

Rusty the good news is nothing really has changed in hot rodding other than a lot of them are run by computer these days. It's just as expensive as it ever was and the cars are still never really done!

I'm looking forward to seeing your build come together.

airbum

Jim,
Thanks for your positive input! I just picked up a 7.5.l/s 3.27 yesterday and am cleaning and preping it. I may just spring for the trans already built. I really like the ls1's but the Ford f/i 5.0 fits my budget alot better.

Thanks!
Rusty

charchri4

Hi Rusty! I hope you don’t feel you are settling for second best by going with the blue oval. It has its advantages for sure in ease of assembly and is a tried and true set up. My original plan was to build a 302 but for me it was cheaper to do the LS because I already had the donor car. At the end of the day it doesn’t really matter because any V8 in a Miata is a total kick in the pants!

I am in roughly the same transmission boat as you are but for different reasons. The T56 going into my build has a bent 3/4 shift fork and unknown other problems. I would love to dive in a rebuild it and feel I have reasonably good odds of doing so successfully. I have gone through a couple of transmissions in school and as an apprentice but this is one of those few situations that I hesitate and feel experience might be worth paying for. There is a thousand parts in these things that the pros have seen a thousand times and will spot instantly if something is not right. Considering how much work it is to redo if I miss something or get a shim on the wrong side of a snap ring it could be money well spent.

I’m sure bring a lot more experience to the table and an easier, cheaper trans to work with. I’m looking forward to seeing which way you go on it and how it comes out. Are you going to overhaul your diff at all?

PS you do realize as an instructor you are required to do a fabulous build thread for us right?

Al English

There is nothing magic inside a T-5, but there are some things you should know to get the best results. Mainshaft endfloat/preload is one of those things. A good book on rebuilding the trans should tell you everything important.

A lot of upgrade pieces available for the T-5, but a production "Z" is pretty strong. The support for the mainshaft bearing is one of the weaker links. If you decide to rebuild it would be worthwhile to go with a stronger/stiffer aftermarket replacement for that part.

mustardketchup

Hello Jim Stainer,

Sometimes things seem daunting until you jump in with two feet. I bet you can tackle that bent shift fork. You did mention “unknown other problems.” Maybe the bent fork is causing your other issues?

Some years ago, I had to swap a salvage yard 5 speed manual trans into my father's 1986 Acura Legend. The car was stolen and the thieves did violent donuts/burnouts in the car: they burned the front tires down to the cords (absolutely no tread was remaining), and eventually, they hit a curb and broke the transmission case.

Anyway, after putting in the salvage yard trans and test driving, the car would pop out of 2nd gear when I would decelerate. I had never seen the inside of a manual trans, and I was very hesitant to tear into the trans. However, I had to get my father's car up and running quick, because I had access to the lift at the shop for that one day only.

I pulled the trans back out, opened up the cases of both transmissions, visually identified a worn 2nd gear cluster synchro on the salvage yard trans, swapped it out for the "good" 2nd gear cluster from the original trans, put the trans back together and then back in the car.

Everything worked out fine - and my initial fear of tearing into something unknown was obviously exaggerated.

Manual transmissions are not too scary. My only advice would be to make sure you don't need any special tools for disassembly/reassembly. Just keep your parts neat, your workspace orderly, and things should work out for you.

Whatever path you take, good luck with the end result.

Lawrence Brady

PS - Jim, I took the liberty of sharing your low-buck brake cooling tip with some folks on Moparts.com.

airbum

Jim,
I will try to keep everyone informed but as for a "fabulous build thread" I don't know??? I will do what I can. As for the diff. I am going to tape up around the old seals and vent, sandblast, paint and install new axle and pinion seals and pray for the best for now. Like you said "cars are still never really done!" so I can always come back to it, if need be
Thanks
Rusty

airbum

Al,
Still on the fence with the trans, buy built like I want or jump in and try it myself ? Forty years ago I would have jumped right in no question. Now, I am leaning toward buying built. I am still looking both ways though.
Thanks!
Rusty

Gunpilot

Found my receipt today. This is who I used : Smart Parts Auto

Tremec Mustang T5 Transmission For Sale

I called them and had the gear set changed for an additional $100. Delivered to my door. It was the best price I found, and it is like new.

airbum

Gunpilot,
I looked at there web site and prices look good! I am going to give them a call.
Thanks!
Rusty

charchri4

I know that place and they have a transfer case shop not very far from me. I've never heard anything bad about them. For what it's worth I know their T56s come out of Dallas and they do a lot of stuff on ebay.

Defy_V8_Miata

I went with a 4 cylinder borg warner t5 with my 302 w/ 327 thunder bird rear end. I bought it in hopes of having a faster ET at the drag strip. I couldn’t have been more wrong. The tag code from the t5 said its first gear was a 3.97 which allows me to get to probably 15 mph before its killing the rev limiter. While cursing in 5th gear im at about 3k rpms going 70 mph. My best ET with this gearing has been a 14.9 due to the fact I have to change into 5th gear before the end of the 1/4 mile. Moral of the story is, I am in the hunt for a real transmission and I blew 300 dollars on a used 4 cyl t5.

airbum

Thanks for all the help! I now have a rebuilt t5 with 2.95 and .63 gears. I have sent my K frame, oil pan and hubs to Martin and am now waiting for the kit and stuff to start coming in.
Thanks again!
Rusty

WolfGT

Very useful information in the thread about the gear ratios. I'm working on this issue at the moment because I'm trying to get my transmission on order in the next few weeks. But what I keep coming across is comments like "a more usable first gear" and that this "combination is better". But I think those comments are very biased on what they are trying to accomplish. If they want their car to run the 1/4 mile the fastest with a killer launch, they would prefer a different gear setup than someone that is running autocross and may rarely leave second gear.

Does anyone have some input on what setup would work great on a tight twisty course like an autox? I'm looking for gear ratios for the tranny and the rear that have worked well for someone.

In my research to figure this out myself. I have started to us an RPM calculator that you can put in all the information and see what RPM you would be running at a certain speed. Since all engine setups have different RPM ranges to hit their specific strength, I thought this would be good. With the proper information, I think someone could use this to figure out what they need. Link below.

RPM Calculator

charchri4

That is a little tricky because the venue of the club makes a big difference. I’ve done tiny lots were you never get out of 1st gear, lots of 2nd gear all the way lots and one delightful venue at an airport that I topped out 3rd. However you are spot on to focus on 2nd because the vast majority of autox is shift to 2nd and forget about it.

So with that I've done a bus load of autox with an equivalent set up to 1.78 2nd gear, 3.55 rear end and a 23" tall tire. (225/45-15) My shift light is set at 6200 and every once in a while it will blink at me running a 2nd gear course but not very often. On the other end the only time it drops below 2000 is in a Chicago box or making a U turn around a single cone which is not very often.

Note I say equivalent because my current car is as above but my experience is with a 1.78 2nd gear, 3.73 rear end and a 24.5” tall tire but both formulas work out same final number and both cars turn the same RPMs at the same speeds.

Hope that helps!

V_Session

Hi,

new guy here!

I don't want to hi-jack this thread but my question was very close as the op.

The engine specification is 400 hp @ 7200, 325 lbs @ 4700. Redline at 7500.

I don't find a need for a t56 so I'm wondering what would be the best t5 to use. I want to use the 7.5 differential but still confuse about the gear ratio to have.

The tire will be 225/45-15.

Not a race car, more like a fun car to drive the week end. Not a fan of drag racing either, I mostly want a set up that I can use all the gears.

Thank you
Yannick

charchri4

Update to what I said above. I now have about 1500 miles on the build and all kinds of driving and racing. I love the T56 in the car. Sure you can start in 2nd or 3rd for that matter but when you want to launch the low 1st gear is a delight.

On the other end the 6th gear allows a consistent 25 mpg and puts me in an RPM range you will never hit with a t5 and 3.55s...