Transmission / Overdrive: TKO 500/600 into Avanti console problem

[karterfred88]

This question is aimed at those who have actually done this conversion. As you probably know Tom (sbca96) did quite a write up on his Tremec 3550 install, but back in 2007. His "work- arounds" for the shifter/console interference won't work for me. The TKO shifter tower is different and the "stub" is no longer easily cut shorter to allow passage under the 63 console brace. In addition, I have the choice of using the GM "butterfly" case TKO with the short shaft (6.7) in a $700.00 plus bell-housing (with the joys of using a $500.00 hydraulic T/O bearing), or using a 61-62 T10 bell housing (which I have) and installing a long Ford (7.21) input shaft in the GM case trans. Either will get the trans in the car, but both present the shifter problem, unique to the Avanti console location. To get the shifter back far enough to fit in the normal location requires a "rear extender" which will still have to locate on the stub-under the console, without any contact. My question is how did you deal with this. I purchased a Hurst rear remote shifter ($300.00) but it goes way too far back into the ashtray area (at least by measurements), it is a beautiful piece of CNC machined aluminum, but does not lend itself to shortening the housing enough to work, without cutting it up and welding what was a billet aluminum piece. Ideas? The real problem centers on, the center of the shifter tower being 19.0 +/- inches back from the front face of the trans, verses a needed 23 +/- inches to get it into the console area. The Hurst shifter picture is a photo edited and shortened from the original 8 5/8 to approximately 3 1/2.

[sweetolbob]

Of course, my experience is the T56 behind an SBC but is there a way to drop the tranny mount an inch of so. I know it's tight in there but a bit down would let you notch the housing without looking different on the top? I'm asking as the shifter looks higher in the housing than mine.

[karterfred88]

Not sure that that can be done on a Stude powered TKO as the clearance for the tail housing end is already at the beginning of the frame X-member area and lowering it would cause the drive shaft to bottom on the lower portion of the X. With the front of the engine lowered and angle lessened the engine pulley's would rub the bell crank and oil drainage in the heads would even be worse. Since you have a T56 in there-what is the distance from the front of the trans (bell housing mating surface) to the center of the shifter stub? Maybe I should rethink a TKO and figure out a way to stuff a T56 in, instead, even with the bell housing woes that come with trying to match it to the Stude block..... with no known adapter bell housing like for a Chevy, Ford or Mopar.....no too much fabrication needed--just a thought

[Alan]

Fred, Do you have the Hurst shifter extension in your hand? It would be easy to shorten it. The Quick time housings are around $550 and the QT quarter master TOB's are about $330. I am putting a TKO 500 in my Avanti, but have other projects that come before it, so the tranny sits under my work bench. Let me know what you want to do and we can work something out.

[bezhawk]

The one I'm currently building, (TKO-600) I used the QuickTime bell housing, no adapeters as it is setup for the Chevy bolt pattern. I machined the oilite bronze pilot bearing to extend out from the face of the crank flange 1/4". used a dual friction Chevy Centerforce clutch, a Fordanza aluminum flywheel. I used the stock Stude Transmission mount, and the shifter stub just barely clears the front edge of the opening. I made an adapter that moved the shifter handle back about 3". I ended cutting the top of the stub just at the bottom of the top hole, used the bottom hole to hold the adapter where i wanted it angle wise, then welded the top of the adapter even with the cut off of the top of the stub. The handle still bolts on to the back of the adapter.
I looks very much like SBCA96 pic, or your first one.

[karterfred88]

Fred, Do you have the Hurst shifter extension in your hand? It would be easy to shorten it. The Quick time housings are around $550 and the QT quarter master TOB's are about $330. I am putting a TKO 500 in my Avanti, but have other projects that come before it, so the tranny sits under my work bench. Let me know what you want to do and we can work something out.

The QT cheapest I can find is now $761.95. It was on sale for $678.00 last month--gone!! No info at Holley-Lakewood anymore-number doesn't exist anymore.Yes I do have the shifter, but no it is not simple to shorten, the flange at the end of the extension to the shifter box is machined from the bigger billet size down to the "tunnel" size which is one piece and nicely CNC carved for the pivot pocket. Needs to be sawn and welded unless I can find a "cheap machine shop to duplicate the flange, tunnel and box out of billet shortening the tunnel, just don't know exactly how much till it's in there. I was hoping for an "off the shelf" solution but looks like I may be 10-15 years too late!. I'm leaning on using the 61 bell housing and manual linkage I've located. Not being CASO exactly, but an extra $1,200.00 on top of a new TKO is starting to get silly.

[karterfred88]

The one I'm currently building, (TKO-600) I used the QuickTime bell housing, no adapeters as it is setup for the Chevy bolt pattern. I machined the oilite bronze pilot bearing to extend out from the face of the crank flange 1/4". used a dual friction Chevy Centerforce clutch, a Fordanza aluminum flywheel. I used the stock Stude Transmission mount, and the shifter stub just barely clears the front edge of the opening. I made an adapter that moved the shifter handle back about 3". I ended cutting the top of the stub just at the bottom of the top hole, used the bottom hole to hold the adapter where i wanted it angle wise, then welded the top of the adapter even with the cut off of the top of the stub. The handle still bolts on to the back of the adapter.
I looks very much like SBCA96 pic, or your first one.

I don't see how the QT bell at 6.29" hat height would be even close as Tom used the Stude bell ( 7.0 +/-) and a 3/8 adapter plate and had trouble, no less moving it .7 plus .375 further forward. Have you got a photo? Maybe it will squeeze in with the Stude T10 bell (7.0 +/-) loosing only the .375 from the spacer. I'm in buying mode, but am up for only one install try without spending an extra $1-2K!!

[Alan]

Piece of cake Fred. 4 1/2" to be removed. Box it up and send it to me, I'll make it fit. When it comes to bell housings go to the Racing Stude web site. Then go to Stude. performance page 12, half way down the page you will see an article entitled SFI Bell housings. Read all the article and when you get to page 3 you will see how much I payed for mine.

[karterfred88]

Piece of cake Fred. 4 1/2" to be removed. Box it up and send it to me, I'll make it fit. When it comes to bell housings go to the Racing Stude web site. Then go to Stude. performance page 12, half way down the page you will see an article entitled SFI Bell housings. Read all the article and when you get to page 3 you will see how much I payed for mine.

Yes time marches on--and speed parts are getting expensive at a much greater rate than inflation!! I looked at Summit in December, waiting to put aside the $678.00 for it on sale--now !!!!! I have the 61 T10 bell and Al flywheel, and Texas Barry has the clutch linkage set aside for me to convert from my "power sh**t ". I would slap a T5 in from a 88-89 Camaro, but those are getting rare as cores and a total rebuild plus the core is as much as a TKO +/- no brainer there. As I said 10-15 years too late to keep a reasonable budget-it's just a driver quality car. PM me with your address, I lost you old PM with it during the server change.

[Xcalibur]

I put in the ol' GM (Camaro/Firebird) T-5 behind the GM-pattern bellhousing 20+ years ago. I molded a tunnel heightener for the top, built-in shifter rail (or whatever it is) to gain more clearance. That is, I laid fiberglass mat over a length of PVC pipe and cut it to a "half-pipe" the correct length, cut a long-ish rectangle out of the bottom of the console and molded in my new half-pipe. I'm not sure what all your problems are from reading your account but it is possible to get more top-side clearance without "butchering" everything. Also, I molded my own, new cover for the top of the console, eliminating the ashtray entirely, as well. Plus, I made a custom shift-lever and knob. Best of luck.

[karterfred88]

I put in the ol' GM (Camaro/Firebird) T-5 behind the GM-pattern bellhousing 20+ years ago. I molded a tunnel heightener for the top, built-in shifter rail (or whatever it is) to gain more clearance. That is, I laid fiberglass mat over a length of PVC pipe and cut it to a "half-pipe" the correct length, cut a long-ish rectangle out of the bottom of the console and molded in my new half-pipe. I'm not sure what all your problems are from reading your account but it is possible to get more top-side clearance without "butchering" everything. Also, I molded my own, new cover for the top of the console, eliminating the ashtray entirely, as well. Plus, I made a custom shift-lever and knob. Best of luck.

The T5 shifter is different with the "box" near the end of the tail housing, and "pipe" from there to the case for the internal shift rod. The Tremec TKO series are physically different with 3 "movable" positions, but furthest back is limited to the tail housing casting, of which there is only one location.
and the shift rail rod runs inside the case making the "tower" location critical since it can't be moved, that's why there are all sorts of sticks and extenders sold to move it around, but the center stub is still fixed and falls right at the cross bar between the heater panel and the shifter tunnel cover almost touching it if uncut. The various bell housing combinations move that point forward or back within approximately 1 " back or forward but always just in the way. The T5 might be a better fit, a couple of side spacers on your shift lever would center it visually. The new T5 from Tremec is only sold in a "new Ford" mounting case and as I said, a Camaro T5 rebuilt to new is almost a wash with the newer stronger TKO. I'm trying to minimize the unknowns.

[Xcalibur]

I guess that only leaves cutting up the top of the tunnel or... moving the entire thing, engine and all. My only choice at the time was the old T-5.

However, we did put a new HD Tremec in Lange's B'ville Avanti in '15 and though it was a bite to install, I don't recall it being an issue where the shifter came up, but who knows what he used back in 1990 or '91 for a bellhousing to mount his Chrysler-patterned Doug Nash. If you want I can ask him for ya.

[WCP]

A T5 installation (without transmission adapter).

[bezhawk]

Here is the TKO-600 shifter, and where it ended up in the hole. Homemade shifter handle out of stainless. shown in gear, and out. There is a weld the height of the stub on the opposite side.

[WCP]

I guess the critical consideration here is the height of the transmission shifter tower. The lower the transmission, the longer the shift shaft needs to be, with more forward motion of the shaft at the console surface. The higher the transmission, the shorter the shaft with less motion at the console surface. I was able to keep the shaft movement within the block-off plate opening. Something to consider when designing your console shifter closure. As an aside, I like the A/C evaporator plate too.