Advise on tranny purchase
 

Well i'm still pre build but have just about all my parts gathered. still need a tranny. Locally I can buy used up and beat on T5 with the 3.35 first gear for anywhere from $300-600. The best deal I've found for a totally rebuilt with a 2.95 that I want is $1400. That is more than I planned on spending for a tranny.
I wish I'd been able to just find a complete engine/tranny pullout when I started this. I've already got a grand in the engine, another $500 in wiring, and now looking at around a grand or better on a tranny. Oh i guess i still need a bell and a clutch and all those goodies too. Another $500.

I was very lucky my last time out and found a used T5 and bell for $150 on craigslist. The guy was upgrading his Mustang to a 351 and wanted to go with a T56 and blow proof bellhousing so the parts I purchased were just "in the way". Had I arrived earlier he would have thrown in a Pro 5.0 shifter for another $25.

I was not very optimistic that the trans would last beyond a few months but it's now on it's ninth track day and has done almost 20,000 miles without an issue. I was very lucky.

My plan is to replace it with a new T5z for around $1600 BEFORE it eventually goes bad so I can sell it as a working used one for $300 or so. I looked into rebuilds and since most require a working core anyhow the difference between that and "buy a new one, sell mine" is only a few hundred.

If you go the rebuild route you're going to need a core anyhow. Pick up the best looking and feeling (turn it over by hand before buying) used one you can find in the $300 to $400 range. If your lucky you may not need to rebuild it.

Another important note, when I put it in I also purchased an aftermarket shifter with adjustable stops. Much of the wear these transmissions see is due to over shifting or riding the shifter handle with the stock POS shifter. The shift stops all but eliminate this even if you drive with your hand on the shifter all day long. The one I picked up was one of the cheap ebay units for $35.

-Jason

Looks like I found a reasonaby priced fox T5. How useless is the 3.35 first gear?

New guy did a killer write up on that very subject here.

https://www.v8miata.net/suspension-d...1554/#post9746


Jims .02 - and I have no idea if this is even possible but - add 500 to the 1400 bucks and put a T56 in the car. It gets you a 2.66 1st gear and a 0.50 6th which translates to a very usable 1st and a 6th that will pay the difference in gas mileage sooner than later.

Tremec Mustang T5 Transmission For Sale

This place did good for me with the gear ratio I wanted. Best price I found. Looks new and delivered to my door.

Right but as OP said the 3.35 gear ratio trannies are 300 to 600 all day long. It's rare to find the much better T5z version with the proper gearing for a Miata under 1500.

+1 I just put a $54 ebay special on my T5 and wow what a difference it made! It would have been worth twice that easy.

Jim, care to share which one you bought. I need to do the same just haven't made the move.

Oops I was wrong it was only 47 bucks! It is built almost as well as my $175 B&M ripper and really an excellent shifter for the money. It took the shifter throw from about 6 inches to 3 and is way firmer feeling.

** Full disclosure here I put this shifter on my Firebird with a T5 in it not a Mustang trans.

http://i58.tinypic.com/5kobd4.jpg

Nice. I think Latemodel Restoration sells that shifter under their SVE badging.

Jason

Just a word of advice, they do wear out and they sometimes require a bit of finessing to get them to work right. The first one I purchased had about 20K miles on it when the centering rod worked its way to one side and messed up the centering spring on that side. The replacement I purchased for some reason had a ball that was too large in diameter for the transmission's receiver cup. I ended up drilling and tapping a set screw into the center of the first one and making up one good out of the two I purchased. I guess considering that I still have under $80 spent I should be happy.

With the exposed mechanism these types of shifters have make sure to use some type of upside down boot to keep the rain and weather out. I did not the first time around which probably contributed to its premature failure. I used an "Oatey Master Flash" roof vent pipe flashing "grommet" for mine. Part number 140522 at Home Depot.

-Jason

Well, my deal on the fox T5 fell through. The more I think about it, the more I think I should just order a rebuilt with a 2.95 first. Now the dilemma- my trans rebuild guy says I can have a .68 or .80 OD if I go with a 3.35 first, but only a .60 or .66 if I go with a 2.95. The .66 will likely be fine, but I was hoping for a .80. Anyone know why he wouldn't be able to build one with a .80 OD? BTW, I'm running Martins 3.27 diff.

Lots of variables to that question like cam, EFI or Carb and how you are going to be using the car.

With a 23" tall tire (225/45/15) 3.27 diff and .8 OD you run 2400 RPM at 65. With a .68 you run 2100 at 65.

There is no question at all I would go with the .68.

I was more wondering the "why" he couldn't do a .80 with the 2.95 first. Are those gearsets unavailable or some other reason.
He's not available to answer right now which is why I'm asking here if anyone knows.

There are custom overdrive gear sets out there for the T5-Z with 2.95 low.

Here is a gear set to produce .80: T5 Sebring .80 Overdrive Heavy Duty Gear Set

From this page, Astro sells a 55 tooth countershaft gear and a 31 tooth mainshaft gear. Pair those up to get a .73 overdrive when used with a 2.95 low. Astroperformance.com - Your Manual Drivetrain Specialist

Vintage Performance (Volvo guys) actually have a custom gearset that produces .90 overdrive in a 2.95 low box. Performance Parts - Vintage Performance Developments

OK, I got a reasonable explanation. I can get the .80 gear but not for the price he quoted me.
Anyways, I ordered the tranny from him with the 2.95 first and .66 OD. He needs to know what tailshaft gear is needed. I don't understand this at all, so maybe I'm translating this incorrectly, but from what I can remember him saying- there were 3 different tailshaft gears used....something about the speedo. Yellow or black or cream......anyone know what this refers to? It's not the red speedo gear. I mentioned that I will use a red speedo gear, but he was talking something about the tailshaft gear.
Any tranny experts here?
??

It's the speedo drive gear (drives the red driven gear). They come in different sizes. There are calculators on the web that the stang guys use to figure out what they need (variables are tire size/rear ratio/driven gear/drive gear). Google it.

Jason

Both gears come in different sizes, the tailshaft gear and the driven gear. The tailshaft gear only comes in three different tooth numbers but the driven gear can be purchased in a plethora of different tooth counts.

Here's a handy calculator to find the one you need:

Mustang Speedometer Gear Calculator

I'm glad I found it as I'm in the process of looking into building myself a better 7.5 rear using a 3.08 gear set.

-Jason