a different kind of switch

[R3N0]

Hello all, new guy here. So im pretty good with a wrench, but ive come to a situation im not grasping. I have a 1988 Dodge W250 Gasser. 360 with a swirlport build. I pulled the NP 435 out and replaced it with a 94 A518 46RH. viper 2 series from PATC. everything runs great till i hit the gas... with mild petal it accelerates through all the gears no issue. but the moment i give it any kinda real gas i get a loud clicking noise coming from the torque converter area. Not sure whats going on with it. if memory serves me right the torque converter stall speed is about 2000-2200. I only drove it down the block and back as when i heard the noise i slowed down, it went away and i gently parked it back in the barn. any thoughts? something i missed maybe?

1988 Dodge W250 Power Ram
360 bored block crank turned and polished
91' Swirlport heads Valves opened to 2.02 Int 1.96 Ext ported and polished
bored .030 Kieth black hyporetic pistons
Comp Cam .430/.450 lift 260/268 duration 110 lsa 108 degrees centerline
Edelbrock Performer intake
FI Tech 400-600hp go street fuel injection
Lokar Ratfink on the floor shifter
1 3/4 hooker headers to indepentdent dual cherry bombed exhaust
PATC Viper 2 series A518 46 RH transmission
NP 241D transfer case

 

[Dana67Dart]

Welcome and thanks for providing the needed info.

I'll be the first to admit I don't know squat about either transmission.

3 thoughts...


Did you get the crank pilot bushing correct for the application?

Flex plate bolt or weight hitting the inspection plate?

Does it have a lockup converter that's not happy?

 

[R3N0]

that may be my issue, heck all 3 might be... i used the pilot bushing from the NP435, the flex plate is the B&M weighted as my TC didnt come with weights... the TC is from PATC and was suppposed to be rebuit to suit the trans.

 

[R3N0]

Im wondering if the distance on the Flexplate and TC is outta wack. i used shims but if i remember correctly i closed the gap to seat the TC right up against the trans... and now im remembering that i should have left a little space... rubbing the pump wall maybe?

 

[R3N0]

the more i think about this, the more im realizing i have the TC rubbing the pump at high speed as that is the whole point of the "flexplate"... im having a homer simpson DOH moment... just hoping that the small trip to the end of the block and back didnt do any damage to the pump or the TC. thanks for asking me different questions than i was asking myself. sometimes you just need a different set of eyes.

 

[Dana67Dart]

Tc swells a bit under load hence flex plate. But if you shimmed between the flex plate and the TC that at least would be an easy reversal. Assuming no catastrophic damage.

 

[R3N0]

now im wondering what the measurement should be between the flexplate and the TC is supposed to be. not sure if its standard between all FP & TC or if it is defferent between makers.

 

[CudaFactHackJob]

Worn main bearing.

 

[R3N0]

no, no worn main bearing. my measurement on the spacers i used between the FP and TC were 1/6th of an inch off... i put too much in there. readjusting the spacers now and ill repost the result

 

[CudaFactHackJob]

If spacers pushed the edges of the flexplate forward, then the converter would push the center pump gear back; gouging the pump cover. A throughout bearing pushes the crank forward against the thrust main every time the clutch is disengaged; increasing crank endplay. Converters spacers should be installed with the crank pushed all the way rearward to avoid pump damage. Cranks walk forward under acceleration.