350C kicks in hard in reverse....

[Freddie's Buick]

It does'nt happen often, but enough to cue in warning flags. Here's what happens: If I am in a driving situation where I need to shift back and forth from drive to reverse, at times she'll jerk hard upon reverse.

It's hard enough to snap an engine or tranny mount. My U-Joints are in good condition and the idle speed is up to specifications. Like I said this does'nt always happen, but when it does it scares the pants off me.

I'm thinking maybe the safety neutral switch? Any ideas?

 

[chris718]

sounds like hi line pressure ,toobig a hole in the plate feeding the direct clutch ,a stuck reverse boost valve etc .do a pressure test and get back 2 me .i have seen this alot and it is usually remedied by grinding a flat on the reverse boost valve to reduce initial pressure built up in reverse circuit and consequently increasig l/reverse clutch pack accumulation.www.ckperformance.comm

 

[Freddie's Buick]

Uhhhh....

Engines I know, transmissions....well I know how to change the filter.

Anyway, how does one do a transmission pressure test?

 

[chris718]

you attach a pressure gauge to the trans in the same manner you would on an engine to get a correct psi reading when diagnosing a bad gage idiotr lite or engine that is suspected of having inadequate or excessive pressure .then based on the readings you would devise a corrective measure or measures .ckperformance.com 718 626 4315 new york city

 

[Freddie's Buick]

Well,

I do have a good vaccum gage. Were do I attach it to? On the modulater vac line?

 

[87ttypeV8]

problems

when i first start to drive my car and then go to put it in reverse it shifts very dard and gets a chirp from the tires... if i let the car roll for a second in neutral then switch to reverse then it is smoother and not as jerky but i have the same problem

i also just got a new rear end and they said to avoid stress like that such as neutral slams and hard reverse and drive shifts.... kinda scares me since i just dished out 1000$ to repair my rear end and i just want this fixed so any input will help me2

 

[chris718]

the pressure tap has an 11 mm plug you remove and screw the hose into .just like tapping in to your oil pressure switch on the engine .it is located on the side of the trans and on a 350 there are several taps to check pressure in different ranges .if you get a gage and it can read between 75 and 300 psi call us at ck and we will tell u what to do .7186264315

 

[jakeshoe]

87Ttype,
One of the side effects of some shift kits is that you get a harsh reverse engagement.
Also the way the trans was built has some effect.
Reverse uses the direct and low/reverse clutches.
Many builders leave the wavy plate out of the direct for a quicker apply going into 3rd gear, this will make the engagement harder.
Also some builders and some shift kits leave out the accumulator springs and this causes harder shifts and rougher engagement. Usually not the best way to get a hard shift because it fouls up shift timing on the TH350 (broken sprags...).
Also some (most)shift kits use the reverse side of the direct piston for additional holding capacity in 3rd. This may cause quicker engagement into R, because it is already primed with fluid.

 

[chris718]

JAKE ,I HAVE FOUND THAT DUAL FEEDING REDUCES RUFF REVERSE BECAUSE YOU HAVE TO FEED TRIPLE THE AREA THROUGH ONE HOLE .we dual feed our 2004rs in direct too .eliminates drive shaft bumping and clutch burn up when done right .i agree that removing accumulators is done by people who KNOW TOO MUCH

 

[87ttypeV8]

actually my trans is a 200c and is original with almost 78000 miles... just wondering if it could maybe be the engine mounts or the trans mount or something cause it makes a loud noise towards the engine compartment a little and really pulls hard on the rear wheels lately... i dont like it at all

 

[Freddie's Buick]

Hey Chris,

You might want to fix your link. .comm should be .com. Then the link will work.

I see you got an endorsement from Kenne-Bell. I'm getting their torque converter for my THM-350C.

Would you recommend it?

 

[chris718]

thanks and yes .

 

[Freddie's Buick]

Chris,

I'll repost on this thread when I get a chance to tackle that task. Thanks for your help. By the way, I was born in Brooklyn and I lived in Astoria for about 10 years, (Ditmars and 21st Ave).

I know the area were your shop is located. There are many quality shops and tradesman in that area. I admire people who take pride in what they do. And those craftsmen certainly do. It's nice to have people like you on this forum. Thanks for your assistance.

 

[chris718]

can you send us some sun ,we sure could use it .ASTORIA PARK you gotta love it .www.ckperformance.com thanks

 

[Freddie's Buick]

Is the pool still there? Too many memories.....differant world...differant me...Astoria was way cool.....

 

[chris718]

it still is. by the way are we gonna get a gage on it so we can fix it ?

 

[Freddie's Buick]

I think my Vac gage covers the span you wrote about but I'll have to check. I have various fittings. I'll have to also check for fit. Better yet will a vac gage work?

By the way, removing the 11mm plugs will it spill fluid ?

 

[Nordbert]

Pressure gauge

You need to use a pressure gauge and hose with a range of at least 0-300 PSI which is designed for hydraulics. The pressure taps in the case are 1/8"NPT. Safety first!