Joined: Sat Aug 19 2006, 05:03PM
Location: Ontario, Canada
Posts: 2919
I am installing a TransGo TF2 shift kit in my 727. I'm at the stage where they say to grind the throttle valve down to 9/32". I've been trying to figure out exactly what this does.
I could be wrong, but from what I gather, this mod provides the ability to adjust the kickdown linkage to provide WOT shifts at up to 7500 RPM. Since I never plan on shifting over 5000 RPM, I'm wondering if I should not do this mod, or grind it less than they say. Any suggestions?
Joined: Sun Jan 18 2009, 09:54PM
Location: BRUNSWICK, GA
Posts: 120
I do believe that it allows you the ability to downshift into first at a higher speed. so if your wanting to manually shift then you can slap it into first and it will shift. I did it to mine and believe that is the result. it works nicely but I will be honest if you accidently do it at a high speed you can mess up some things because it will downshift.
Joined: Fri Mar 13 2009, 11:21AM
Location: San Marcos, CA
Posts: 713
The replacement shift valve that comes in the kit allows the downshift at any speed. The grinding of the throttle valve is indeed what allows the higher full throttle automatic shifts. I've only ran the TF1 in my street cars, that doesn't call for the grinding of the valve. It is only a 1 hour job to R&R the VB if it doesn't work right. It won't cause any problems not grinding it though. Don't run the pressure up to the race setting for the street, too hard on motor mounts and uncomfortable. The race car I built the trans for, broke the low-reverse strut when the trans was put in reverse, TransGo had us drill a hole in the apply piston to relieve pressure so it didn't break the strut again. My $.02
Joined: Fri Dec 22 2006, 08:41PM
Location: Warrenton, Virginia
Posts: 1366
After reading all this I'm glad I decided NOT to do the shift kit thing... I'm looking for nice crisp shifts to get me up to speed quickly but I won't be racing the car or anything....Just some spirited street driving and that's it. I DON"T shift the tranny manually and really see no need to for the kind of driving I do. Only time I manually shifted was when I selected 2nd gear when driving down a mountain road...Even then, it probably wasn't necessary (my car has Budd disc brakes and believe it or not they were up to the task of slowing or even stopping the car when driving mountain switchbacks).
My tranny has the part-throttle K-D feature which was installed by Jasper when they overhauled my trans. It is a very nice feature, even in a 440 powered car!
With all that said, I wouldn't mind firmer more positive shifts....Any ideas??
Joined: Fri Mar 13 2009, 11:21AM
Location: San Marcos, CA
Posts: 713
The SK-TF is a subset of the Transgo TF1. Easy to install (you have to drill one passage in the VB). I have installed ether this or a TF1 in every 727 I've built. Keep everything immaculate and you won't have any problems. The trans will shift more efficiently and last longer. My $.02
AH...Yes!!!. Last year while grinding a valve,..my hand slipped and got a little to close to the grinder! Cheap leather gloves DO NOT cut it! !nope ! Should of had my welding glove on. Oh well,..flesh grows back as i'm sure we can all attest to that. You could try Type "F" fluid to firm up your shifts or step up to the B+M trick shift fluid as it is a premium fluid and will extend the life of the trans also.
Many years ago I had the trans rebuilt on the Monaco, and I asked for firmer shifts. All they did was upped the line pressure, and it shifts GREAT. Chirpy tires with medium to wide open throttle, and regular shifts are nice and crisp.
Joined: Fri Dec 22 2006, 08:41PM
Location: Warrenton, Virginia
Posts: 1366
I'll try your advice, Jazz!! Pretty much that's all I'm looking for...firmer, more positive shifts and consistancy. Like I said, no intention of racing the car. To me, she is really quite fast Enough !drive
Considering the chassis, brakes and general AGE of the car, it's fast enough now to become PRETTY scary Pretty quickly !driving
At least it is fast enough to be enjoyable to drive and keep up with modern traffic (bunch of race car wanna be's).
Joined: Sat Aug 19 2006, 05:03PM
Location: Ontario, Canada
Posts: 2919
To follow-up on my original post: I called TransGo and spoke to one of their techs. They said that if I did not grind the throttle valve when installing the TF2 kit, then the car would never shift out of 1st gear on a WOT launch. BOOM! So I ground the throttle valve as instructed in the kit.
I asked him what in the TF2 kit could be considered "optional". he said: 1. grinding the governor valve to allow downshift to 1st at any speed. 2. There is a hole in the separator plate that is to be enlarged "for TF1 only" and a checkball that is to be removed "for TF2 only" in the instructions. If you drill out the hole but keep the checkball in, the 1-2 shift will be somewhat firmer than stock. If you don't drill the hole but remove the checkball, the 1-2 shift will be much firmer than stock.
I did not do #1. For #2, I chose to remove the checkball. If I don't like it, this change is reversible. Drilling out the hole is much more difficult to undo.
While I had the VB out I also did some other mods to it: - reinforced two weak areas that are prone to cracking on pre-69 VBs. - added a part-throttle kickdown module.
Once I get the car back on the road with all these mods, I am hoping to write a tech article for the Dock on what I did and how it worked out.
Joined: Thu May 01 2008, 11:15AM
Location: Chicago,IL
Posts: 2868
I would have done both 1 and 2 I find it very annoying to not be able to get down into 1st gear at all costs. There's been a time or 2 I needed down into 1st to 'maintain pace' and it didn't downshift by itself. 727's tend to get very harsh on the 1-2 shift pretty quick and not as much on the 2-3, so I think you'll find you prefer the softer 1-2 to more closely match the 2-3 and to not be jarring in low throttle upshift.