727 first to second bind-up problem

I am having a problem with my 727 that I just rebuilt myself in my 71 short box (the tranny is a 77). It has all new clutches, steels, and bands. The low/reverse band is kevlar lined. I also installed a Transgo TF-3 full manual valve body kit at the same time. My problem is that sometimes, not all the time, it seems to bind up when I shift from low to second. It only seems to do this when I am moving slow, I have not had it do it under hard acceleration. When it does bind up if I am on the gravel in my driveway it will drag the tires to a stop, then it will take off like it is ok. If i give it some gas when it does this, the truck will slow way down, but seems to come out of it. The engine doen not "free wheel" when it does this, it stays under load. Any ideas????? Also should this valvebody need the kickdown hooked up????? Other than this the tranny seems to work great and has a very firm shift. Thank you in advance for any input.....

does the TF-3 have low band apply ? if so the front band is grabbing before the rear releases .

what ratio from lever and what type of band ? also the type of front servo ? this info might help someone with a bigger clue than me ?

A '77 steel separator plate should have a restricted orifice that feeds the rear servo, did you enlarge the orifice? If so to what size?

I know my kickdown band is the flex type, with a stock 2.9:1 lever. I adjusted the bands to the specs in my 1966 plymouth service manual. I did drill a bunch of holes out on the seperator plate to 3/16" Not real sure which ones go where, but did exactly as the directions show. I put a blockoff plug in the passage to the shift governer, and a restrictor in the passage to either the direct clutch or the forward clutch cant remember which, but did as the pictures and directions showed. I think it is a low band apply valve body, because it will compression brake in low when I let off the gas. I have the late style servo pistons, and the TF-3 kit had me put a spacer in the low/reverse piston to block the cushion spring. I also changed the large springs in one or both of the servos according to the directions. Its funny it only does this intermitantly, because I backed down my driveway and took off, and shited first to second then to third several times, and sometimes will work perfect, then sometimes will bind up. I am wondering if it might be a servo hanging up or something. It also has a low reverse drum out of a 62 pushbutton tranny because the old one had been too hot. Also wanted to note, when it does this if I shift back to low it comes out of it instantly, but when I shift up to second it will do it again. I cant remember, but I think it came out of it when I shifted to high also. Thanks again.....

UPDATE, I just went out and drove my truck again. It was going about 5 MPH when it binded up I let off the gas and let the tires drag to a stop on the gravel. I tried to accelerate, and the truck tries to lurch ahead, but wont move, I then (while sitting still) sift it to high or low (doesn't matter) then back to second, then it is fine. Seems to be something sticking? Also, I am wondering if the kickdown band adjustment I used was for a 66 type band. I think they are different, Might be too tight? Thanks......

I would check the rear band first, but it may be the over-running clutch? Did you get all the springs and roller installed correctly?

I never did take the overrunning clutch apart, but it did look like it was in good shape, and seemed to work as it should. It would run in one direction but not the other. Does anyone know of a good low/reverse band adjustment? Thanks....

what did the kit instructions tell you to adjust the bands to ? using specs for a 66 to adjust a modified 77 isn't a good way to go , also that 2.9 lever might be part of the problem , that ratio will apply the band way too fast , you should have at least a 3.8 , preferably a 4.2 .

also you having to replace the rear drum ??? sounds like that trans may have had an issue before ?

contact member randy J and buy his billet servos , you are going to blow out that rear servo eventually with the higher pressures and the heavier spring from that kit .

I do not know if the tranny was working before I rebuilt it or not, as I bought it as a core. The old rear drum had some heat spots, probably could have been used, but I had one that was like new so I used it insted. The specs I used had me torque the bands to a certain inch pound figure than back the adjuster out so many turns. I think the kit had another method where you tuned the shaft and tighend the band until it stoped the drum then backed it out so many turns. I might try that insted. I thought the 4.2 Levers actuated the band fater than the 2.9???? I would think the problem would occur all the time if I had the wrong lever or incorrect band adjustments?? Thanks

The 2.9 lever isn't ideal but it has been used an many TF's without problem; the low ratio levers should be adjusted looser than other levers, try backing out 2.5 turns.

All of the problems seem to point to a problem in the rear band/servo except for your statement "I tried to accelerate, and the truck tries to lurch ahead, but wont move". Did this happen with the shifter in "1"? If it did, there are multiple problems because a rear band problem wouldn't prevent the vehicle from moving.

When my truck was trying to lurch ahead, It was in second gear. I am thinking its in the valvebody or the low reverse servo. Low reverse servo piston could be binding in the bore possibly.....Thanks

I also just noticed while reading old tech articles on here that the Transgo TF-3 needs the kickdown linkage tied all the way back. Mine is just hanging loose right now.... Maybe that could be part of the problem????? Cant tell now that I have just pulled the engine out......I guess all I can do now is sit and wonder about it......

The throttle pressure linkage won't cause the problem you're having.

The total bindup in 2nd points back to a problem in the rear band/srevo.