Transmission Replacement Options

My syncros for 3rd gear are shot. Shifting in and out of 3rd gear creates nasty grinding sounds. I figure the higher torque of the 347 motor (425 ft-lbs) caused the tranny to give up the ghost.

So its time for either a rebuild or buy a new tranny. What does the forum think of the following options. Should I rebuild the TR-3550 for $2000 or purchase a new TKO 600 unit for about the same price? Other more expensive options include upgrading to a Jerico tranny and multi-plate clutch or to change the current 3550 into a dog ring tranny. The cost of the Jerico system is $11,000, and the dog ring option is roughly $3000.

What have you guys done with the most success? Please share your experiences. Thanks.

Jerry

wellllllllll....first reaction is your rebuild price is WAY out of line. I ran a TKO600 without oil and ruined it completely except the case and it cost 1200 to rebuild. Second, I had a TR-3550 (I think they are called TKO2) rebuilt by the same company and he used many of the parts from the TKO500 (I seem to remeber it was a closer match to the older 3550 than the TKO600) and the tranny has been solid with much more power than your 425 ft-lbs. (we are closer to 600 ft-lbs).

The guy I took it to was recommended by everyone I talked to. He is known nationwide as one of the foremost tremec guys. He mostly drag races but he has developed his own shifting forks and many other tricks. Everything he has told us has been 100% accurate. His rebuilds (if you request it) are not to factory spec they are his way and they WORK. The company is http://www.promotionpowertrain.com/ and we deal with Walt (the owner). When we bought our TKO600 we had him make the mods to brand new trannies.

I have rebuilt about 4 trannies with him all FLAWLESS.... We have not needed to rebuild one that he has messed with yet (except the one that was missing oil for a few laps at sebring...ooops). I would tell him you want what we have (If you want my co. name and info so they can find his notes just let me know....he keeps perfect records of what was done to everything).

I would get a better shifter (pro 5.0 or hurst or whatever walt says for your tranny (the 500/600 comes with a hurst). I would get a shift stop kit (mandatory). I would have him use the 500/600 main shaft which is a stronger alloy. I would have him use his propriatary shift forks and other road race secrets he has. I would talk to him to make sure you setup the clutch EXACTLY right. The trannies are sensitive to clutch setup.

This guy knows his Tremec. You wont need anything else. He talked us out of dog rings. Dont listen to me call Walt and talk it out with him. I am pretty comfident if you ask around the tremec circles they all know of promotion power train......

:2cents:

Thanks Brian for the info. I called Walt at Pro Motion Power Train today to see what his advice and price would be for a rebuild. Unfortunately we traded messages. I'll try him again tomorrow.

My syncros for 3rd gear are shot. Shifting in and out of 3rd gear creates nasty grinding sounds. I figure the higher torque of the 347 motor (425 ft-lbs) caused the tranny to give up the ghost.

So its time for either a rebuild or buy a new tranny. What does the forum think of the following options. Should I rebuild the TR-3550 for $2000 or purchase a new TKO 600 unit for about the same price? Other more expensive options include upgrading to a Jerico tranny and multi-plate clutch or to change the current 3550 into a dog ring tranny. The cost of the Jerico system is $11,000, and the dog ring option is roughly $3000.

What have you guys done with the most success? Please share your experiences. Thanks.

Jerry

Jerry,
I used a Long shifted Jerico 4 speed with a tripple plate Tilton clutch in my last race car. This was an amazing setup to use in comparison to the synchro box that I had in the car prior to fitment of the Jerico or for that matter the current setup in my Panoz. I stripped the Jerico prior to fitment and was really impressed with the engineering in the box, particularly the fool proof shifter arrangement that prevents selection of more than 1 gear set at a time (yes, apparently this can happen in some synchro boxes).

This combo dropped lap times in my old car by around .5 - .75 of a second a lap through a combination of lower clutch rotating mass (down from around 45lbs to approx 20lbs) and speed of gearchanging.

If I had the cash, personally I would go for the Tilton/Jerico setup for my Panoz hands down. Problem is this is a large chunk of cash to spend for the benefits offered.

I have just bought a forged 347 shortblock for my car (2nd hand out of States via E Bay) and as part of installation I will be fitting a button flywheel and Tilton tripple plate but will retain the Tremec 5 speed.

A couple of things to think about regards dog ring boxes and tripple plate clutches;

1. Dog ring boxes will select what ever gear you shift to no matter what speed you are doing. If you get it wrong the consequences can be expensive............
2. Dog ring boxes need to be shifted really positively. You cant baby shifts or the dogs get a thrashing and this can cost money to feed (no pun intended).
3. Tripple plate clutches are not shed/trailer/pits friendly. They are often like a switch........they are in or out. This can make the car harder to manage off track and can be harder on engine and trans mounts, driveshaft uni's, bellhousing etc etc. The shock loading of engagement can = more fatigue.

If you get a dog ring box and tripple plate well set up though, there is nothing to equal them on track regards sheer driving enjoyment.

Happy shopping, Kel.

I will post results of a Panoz specific kit for the GTS race cars from this weekend, we just put togather a complete package to fit a Direct Shift Jerico set up in the Panoz. This is the same type of transmission used in the Nascar COT cars. I will also post some pictures.
Matt

If I had the $$ I'd retrofit a sequential gear box to my GTS. The Fellow on the West Coast who has the GTS on ebay has a sequential box in his car. I called Sean Hyland and got a quote of $15,000 for a sequential.

How is a Jericho different than a sequential?

Bench rebuild should be $500-600 unless big damage.

BTW we've had some hard shifting (not grinding sounds!!) that turned out to be corosion on the shifter ball. 2 squirts of WD40 and smooth as silk....sometimes you get lucky.

Kevin

I will post results of a Panoz specific kit for the GTS race cars from this weekend, we just put togather a complete package to fit a Direct Shift Jerico set up in the Panoz. This is the same type of transmission used in the Nascar COT cars. I will also post some pictures.
Matt

Curious to see this.

would like to see this fit our LS1's now.. :o)

On my (new to me) GTS; I had to replace my spherical bearing on the shifter handle. It was cracked-kept getting stiffer-made the difference of literally missing shifts to being very smooth. I had tried the WD option-before disassembly-not corrosion in my case.

My transmission seized up from a shift from 5th into 3rd. I made the gear but I literally cant budge the shifter handle to change a gear or to put it into neutral. No grinding or clunking noised when it failed. It definitely is not in the shifter spherical bearing as I just replaced it and it was very smooth.
Has this happened to anyone else-input?

Does the clutch ingage, and disengage the tranny? If the clutch is okay, then it could be bad syncros.
No grinding in and out of 3rd before it got stuck? Last couple of shifts were okay? Have you had a chance to drain the fluid and see how much metal is in it?
Jerry

Yes the clutch still engages. I was able to be pull towed off the track with the clutch pushed in. No grinding, no prior warning. Literally just stuck solid after the shift. 1st thing I did when I bought the car was replace with the GM synchromesh fluid. I haven't torn into it yet so see how it looks now.

I have had this problem many times. The gear selector "hockey stick" in the gear box can slip past the gate and lock into gear while the transmission is stuck in another gear. the shift lever feels like it is welded in place. I would find this problem in a quick 4th to 5th or 3rd to 4th up shift mainly. It usually would happen in the heat of a battle, and the car would be stuck in gear. It usually does not need a rebuild to repair is the good news. Take the middle cover off the gearbox and you will see the selector mechanism. With a small pry bar or screw driver pop the selector back into neutral position and you gear box will work again. How I fixed allot of this problem is two part, one slow down the shifts (which for me was really hard to do) second I had my transmission specialist hard weld the selector up so that is was a few thousands wider so that it is less likely to over shift. I lost several races to this problem and killed my Runoffs as well because of this. We need to all petition the SCCA for a Jerico gearbox, the TKO sucks....

Racer9007 I am sorry that you have had such bad luck. You need to find a better Tremec support team. The TKO is a good tranny with some minor upgrades that are all SCCA legal. Send your tranny to Walt at Promotion and get his internal upgrades and a shift stop kit design exclusively for racers and allow you to BANG gears. Now all I have raced is a 911 with a G50 and the GTS so maybe a Jerico is worth it but the shift stop will end this stuck gear issue.

lots make it but I would buy Walts:
http://www.promotionpowertrain.com/TRANSMISSIONS.html
scroll down and its list as Stock Shift Stop Kit for 79 bucks

here are some others (better pics)
http://www.streetrodderweb.com/tech/0602sr_six_speed_transmission/photo_13.html

http://www.keislerauto.com/index.php?/adjustable-shift-travel-stop-plate-t45r/t5.html

Lets petition SCCA for straight line performance and a better more reliable engine.

Matt that may be the best news I have had today. I don't think I would say that I am soft on the shifts. Does anyone have time for that!

Brian, thats got to be the ticket. I love the price tag. Not even in the Thousands $ as I am getting accustomed to. What a bargain.


How about getting SCCA to allow for aero mods so we can have some real fun. The irony, we get booted from SCCA STO because we have the advantage of tube frame construction. On the other hand we are competing with 650HP Vipers. Thinking about it, since NASA obviously allows aero (looking at your car) that may be enough reason to switch. This really pertains to the other tread doesn't it..

I never found this shift stop before. I dont have any damage to the shift forks, but the shifter slipping out on a side load shifting. If this fixes it, that would be great! I will check it out!
Matt