sutyak's TR3650 Rebuild/Upgrade

[sutyak]

First off I know there are stronger transmissions out there. This is a first a learning experience and second functional. My car currently makes 630 lb-ft torque through the stock TR3650, which is a recipe for disaster. (This is how I bought it) This is my first complete transmission overhaul, so bear with me. This isn't meant to be a how-to, but if others find it useful then excellent.


I purchased this TR3650 knowing it had a 3rd gear issue. It is supposed to have been originally built by American Powertrain and rated for around 700 lb-ft torque. All I can tell by looking at the internals is that it has a 26 spline input shaft and bronze shift fork pads (or had).
Upon getting it apart I found the 3/4 for pads had come off completely, and basically all the syncros needed replaced.
Oh well. Time to upgrade it even further. My goal now is to make it strong enough to handle whatever I want to throw at it, and learn something in the process.


I'll be replacing all syncros, blocker rings, bearings, seals, and upgrading the shift forks. So basically a complete overhaul instead of just a 3/4 syncro as hoped. The syncros and blocker rings will be stock. I have an email in to American Powertrain to see what else may or may not have been upgraded. I'm hoping the gears themselves are not stock.
I'll be going with billet shift forks and bronze pads from AMP.

The original owner got back to me, and this is what the transmission is supposed to currently have in it. This would have been the Extreme upgrade. (From American Powertrain):
Our 3650 Plus runs $1495 + $250 core and is rated at 500 hp 495ft/lbs of torque. It includes a new "gorilla" 1/2 shift fork, Cryo Hardened 10-Spline Input Shaft, Bronze Shift Fork Pads, Dual Hardened Fork Pins 1-4, Upgraded Low Alloy Steel Bearing Retainer,
All OE New Components (where needed), New Bearings and Seals,
Carbon Fiber Synchros, Complete New Small Parts Kit, 24-Month Warranty, 24/7 Technical Support.


The 3650 Extreme is a 700 hp 600ft/lbs rated box that includes everything in the 3650 Plus but we add a cryo treated 26 spline input shaft and billet key on the 3/4 syncro. This one is $2095 + $250 core charge. 2 year warranty and 24/7 Tech Support access.

[HERE] is the rebuild manual I am using. PM me if the link goes dead.
Due to my garage not being heated, I'm rebuilding the transmission in my basement and sharing some gym space.

[sutyak]

[sutyak]

[sutyak]

Something is missing...
No bronze pads!



The actuator spring for the 3/4 syncro is also broken.



Teeth on all the sliders are worn:

[sutyak]

The force put on the bronze pads wore out the inside of the 3/4 shift fork:



I found the bronze pads...






Time to pull off everything.

[sutyak]

Here is a close up of a syncro blocker ring. The material inside is what grips the cone of the gear in order to gracefully syncrhonize the gear to the shaft speed. If that material wears out, then the syncros become useless. This one still has enough material to function properly, but I'll replace it anyway.





3rd gear removed. Need to make or buy a tool to pull off 2nd. I have a puller, just not one thin enough to get behind the gear.



Here is a stock photo of the AMP billet shift forks I'll be using. More photos once they come in.

[sutyak]

This is where I am today 2/20/2016. Once parts start coming in I'll continue the rebuild and post more photos and details. :CHEERS:


All the gears themselves look great. I'm sure the bronze is much too soft to do any real damage there. The bearings are scored but probably still usable. I'll likely replace them anyway, which means I'm looking at having to deal with bearing preload and shimming.

[TooFast98Cobra]

Wick Can Answer.QuestionS For You If.needed. He.builds These In His sleep

[sutyak]

Wick Can Answer.QuestionS For You If.needed. He.builds These In His sleep

Awesome. I'd like to know how to identify upgraded gears.

[gmkillr]

Yes, Wick (Rob) is the man when it comes to manual trans!

[sutyak]

I sent a PM to Wick to pick his brain. I figure he'll set me straight on a few points.

I pull off 2nd gear today. That is as far as I'll get before taking the rest to my buddy's press. There I'll remove reverse and first in order to replace the syncro assemblies. Since those haven't arrived yet I'm back to waiting again. I haven't actually ordered the blockers rings and bearings, as I want to make sure I buy the best the first time.


For my own future reference I took a few minutes and labeled the main shaft:



I removed 2nd gear by pulling it off with the 1-2 syncro slider. I only did this because I'm not reusing the slider. It turns out it didn't damage the slider whatsoever.



A photo of the 3-piece syncro used for 1st and 2nd gears. This is 2nd gear. The inner piece is the consumable/replacement piece that comes in the blocker ring kits.



Definitely take care with the shaft and secure it with wood in a vice to keep from damaging it.



There are a few places where small steel balls are used to keep spacers properly located. Don't lose these.


One last photo until parts arrive. Trying to keep things properly grouped to limit confusion.

[sutyak]

Well, now I need to make a decision. I determined that this transmission has the factory gear set (3.38 1st, etc) instead of the upgraded 2.90 1st, etc. This means it will hold around 525 lb-ft torque (estimated) instead of over 700, which is what I was told from the guy who sold it to me. Clearly he meant hp instead of tq. My car already makes 632 lb-ft of torque at the wheels (so 700 at the crank), which means I'm still behind even after I build this transmission.
I do have the option of switching to the stronger gear set for a mere cost of $1,845! from Pro-Force.


So now I need to determine a course of action. Ultimately I WILL complete building this transmission, whether I use it for myself or sell it.
1) Build the 3650 with current gear set ($1,500 investment) 525tq (estimated). Downsize the power adder.
2) Build the 3650 with upgraded gear set ($3,400+ investment) 700tq+
3) TKO 600. Still talking with American Powertrain about this option. ($2,900+) 600tq
4) T56 of some variety. Magnum? $3,500+ 700tq+
5) Auto of some variety with overdrive


Ultimately an auto would work best with the turbo, but I'm definitely getting out of my comfort zone. I've never owned or even worked on a high horsepower car with an auto.


I have been considering swapping from the current single turbo setup to a mid-sized twin screw, and match the torque to the transmission rather than match the transmission to the max torque potential of the turbo. Or possibly just go with a smaller turbo.

[PaxtonShelby]

Stan Peace builds Astro's and from everything I have heard Astro>G-Force. Stan built the tranny in my '66. You could probably source parts thru him if you want to build it yourself. I don't have his contact info handy but I'm sure you can google him.

[sutyak]

Stan Peace builds Astro's and from everything I have heard Astro>G-Force. Stan built the tranny in my '66. You could probably source parts thru him if you want to build it yourself. I don't have his contact info handy but I'm sure you can google him.

I also spoke with Astro. I believe Astro, G-Force, and American Powertrain all source their custom gears from the same place.

[Martin0660]

from everything I have heard Astro>G-Force.

I'm at the events where this stuff is raced and abused, and I sure "hear" different.

[wick]

I'm at the events where this stuff is raced and abused, and I sure "hear" different.

In a nutshell, yes. From experience, again, yes.

[PaxtonShelby]

I certainly don't have the real world experience that Bob has. I just read about and was told that the Astro parts are stronger and better made than the G-Force parts.

[sutyak]

Correction, Pro-Force is who got back to me with $1,845. I have not heard from G-Force yet.

[Martin0660]

I have not heard from G-Force yet.

If you are e-mailing or whatever, likely not going to hear back. Call out there and talk to Bubba if you can get him.

Also good sources with Hanlon and Walt @ ProMotion.

[sutyak]

If you are e-mailing or whatever, likely not going to hear back. Call out there and talk to Bubba if you can get him.

Also good sources with Hanlon and Walt @ ProMotion.

Bubba got back to me via email a bit ago. It sounds like G-Force makes the gear set, and places like Astro and Pro-Force are distributors.