BuffaloBillPatri Posted January 17, 2011 Share Posted January 17, 2011 B&M rebuilt TH400. Part throttle shifts seem fine. I have ground the Governer inner weights as much as possible and still have a seat for the springs. WOT Shifts are unchanged at 4200 RPM? What's going on? Thanks BBP Quote Link to comment Share on other sites More sharing options...
BuffaloBillPatri Posted January 17, 2011 Author Share Posted January 17, 2011 http://www.dragracingonline.com/technical/vi_9-bm-1.html Lighter inner weights = higher RPM WOT shifts (except for me) BBP Quote Link to comment Share on other sites More sharing options...
wallaby Posted January 17, 2011 Share Posted January 17, 2011 That's a toughie. The write-up seems clear enough...I'm trying to imagine why it wants to upshift early even with lighter weights. The text does mention that the governor pushes a plunger. The plunger is held outward by a spring and when the governor spins fast enough it overcomes the spring and pushes the plunger inward. I'm wondering if maybe the spring holding the plunger out is too weak? They don't really mention any spring kits for that, or spring shims or anything... Maybe a call to the B&M guys is in order. Quote Link to comment Share on other sites More sharing options...
CrazyDavey Posted January 17, 2011 Share Posted January 17, 2011 you need to get a kit from TCI or someone like that for an assortment of weights and springs. There is not a set formula, every trans is going to react different. It's simply trail and error with different combinations until you get the result you want. You try a set, see what you get, catalog it and if it's not what you want you try a different set/combo. I managed to get the Monte from 4800 to 5700, I have a friend who got his up to about 6100 but it's on the edge of street drivabliity. Dave Quote Link to comment Share on other sites More sharing options...
BuffaloBillPatri Posted January 18, 2011 Author Share Posted January 18, 2011 My WOT upshifts can't be delayed by having gear selector in Low or 2nd. This is the way a TH400 works unless it has been modified (I think). I aparrently don't have a shift kit from B&M. Someone on another site suggested the kickdown solonoid. I adjusted the switch & now 1->2 WOT upshifts at 5500 RPM. Unsure about WOT 2->3 as I had my GV OD on auto. More testing this PM. I still want about 6400 RPM WOT upshifts, will that require stiffer governor springs? BBP Quote Link to comment Share on other sites More sharing options...
BuffaloBillPatri Posted January 18, 2011 Author Share Posted January 18, 2011 Results: WOT 2->3 upshifts at 6300 RPM, 1->2 still at 5500 RPM This is the 1st time that I got up on my 6500 Lunati HR cam, pulls well between 5000 & 6300 RPM. No float noticed of Lunati HR lifters. I have good PAC beehive valve springs, Titanium retainers, Scorpion rockers, & Smith Bros pushrods. Is there any governor spring change that would raise my 1->2 5500 RPM upshifts without raising my 2->3 ? Thanks, BBP Quote Link to comment Share on other sites More sharing options...
overdrive Posted January 18, 2011 Share Posted January 18, 2011 Quote: My WOT upshifts can't be delayed by having gear selector in Low or 2nd. This is the way a TH400 works unless it has been modified (I think). I rebuilt mine and added a shift improver kit. It stays in low or 2nd until I upshift. I don't remember what rpm it shifts from 1-2 at when in drive, but it's low. I think maybe around 4500. I like shifting it. Have you done the shifter mod. to keep from going from 1st to 3rd with manual shifts? It works great. Dan Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.