blocking off accumulators...good or bad?

[OneLethal87GN]

It seems everyone has a different opinion on what mods to do for better shifts. I've seen where some people block off all accumulators completely instead of blocking holes or drilling them bigger or whatever. What drawbacks does this create? Is it better to block them off or do the usual heavier spring bit? Mine had the feed hole in the accumulator made smaller by hammering a small orifice into the hole. It's hard to tell how big a difference it made since the valve body is not a performance body. It does shift pretty firm with the current mods. I have Bruce's shift kit, the wider band, the 200 servo, and the aforementioned accumulator mod. I will either have my BQ body repaired or get a perfromance one put in soon. Thanks in advance.

 

[OneLethal87GN]

Anybody????

 

[84ZZ4]

I haven't done it on a 200-4R, but I blocked both the 3-4 and 1-2 accumulator on the THM325-4L in my Toronado, and it really seemed to help the shift quality. Their main purpose is just to absorb the instant shock of the fluid directing the shift, and I've found that doing this on a stock transmission gets rid of a lot of the slipping feel and gives you a more positive shift.

If other mods have been made to increase shift firmness I'm not sure how good an idea it is to block them completely.

Edit: Forgot to mention I blocked mine by stacking washers underneath it until the piston couldn't move. I didn't block the fluid passages.

 

[OneLethal87GN]

What is involved in blocking them off? I'm not a tranny guy, but was just wondering what you do to block them? My shifts are firm due to the race band, big servo and shift kit. However, they are not as strong as I'd like due to a non-performance valve body replacing my BQ that had a stacked shift that intermittently came and went.

 

[quickt]

Years ago I blocked off them off. I dont anymore. The only ones you can block are the 1-2 and 3-4. Some of the non perf VBs will shift as good as the BR VB and a few even shift better. You can use a checkball to block the 3-4 and drill the 1-2 out a little and also use a checkball there to block it off.

 

[GNeric]

I agree with Lonnie. I used to block them off a long time ago. It's fun for a bit then the cops start to follow you. Not to mention the stress of banging each gear at all throttle positions, if you have a stock 12" size converter. Changing spring rates and orifices works better imo.

 

[JDSfastGN]

i wouldn't do it, you will end up stretching the case at the band anchor pin and/or breaking the band apply area. I would also think other components would see a lot more wear and tear, especially torrington bearings and non Billet Drums and possible u joints. I know they are expensive but if it comes down to it buy a new already calibrated VB from one of the vendors on here or get to looking for another VB at the junkyard from a monte carlo, BQ Hotair, BRF, even an AA (common caddy VB) can work really well if cleaned up and putting a good shift kit matched with a bigger servo. I know you've been through a lot on this tranny and i think blocking accumulators will only cause you more frustration.

 

[87GN_70GS]

I would recommend limiting the travel some rather than completely blocking it off.

 

[lost2a6]

Wouldn't the acc. also provide a steady pressure to the clutches and/or band during a brief pressure drop, such as during a shift or pump pulses. I think that the best thing would be just to run a heaver spring. I used to have my 1-2 acc blocked off, now I have a very heavy spring in it and I don't get that terrible "clonk" sound when it down shifts.

 

[quickt]

I agree with Lonnie. I used to block them off a long time ago. It's fun for a bit then the cops start to follow you. Not to mention the stress of banging each gear at all throttle positions, if you have a stock 12" size converter. Changing spring rates and orifices works better imo.

AMEN

 

[GNeric]

Hey Lonnie, is the woman in your avatar named Rebecca? Looks almost exactly like an old girlfriend of mine that moved to Las Vegas in 1990.



Boy she was fun.

 

[OneLethal87GN]

The bad thing is most of the junkyards around here are starting to only carry newer model car parts. When I call around to ask for 87 Regal parts they act as if they've been extinct for years or something. The vendors are great but I don't want to spend between 3 and 5 hundred dollars for a valve body. I also called to see if any local tranny shops would try to fix mine and all seem to only want to rebuild my tranny than do small work. The stacked shift is kinda weird in that it seems to only occur under light throttle. When I give it 25% or more I don't remember the stacked shift being there. I believe the guy that tried to fix my valve body tried a stiffer spring and also cleaned out the bores. It only occurs after shifting to second so would it be that part of the valve body? His cleaning did alot to get rid of the shift but it would still occur from time to time. Could you make the bore bigger and install an over-size valve? I really don't want to block the accumulators either but this generic valve body definitely doesn't make heavy throttle shifts firm at all as compared to the BQ body. Who sells performance valve bodies relatively cheap? Can a non-performance valve body be made into a performance body? I already have Bruce's shift kit installed so is there anything else that can be done to the body? Thanks for all the help so far. I want to get this tranny straight because I am still thinking of selling the car and want it to be in the kind of shape I'd want if looking a GN.

 

[Lee Thompson]

Me of little mind

Want to know what you are refering to as a stacked shift.

 

[OneLethal87GN]

Under light throttle the car would shift from 1st to 2nd at @15 mph. After shifting into 2nd it would immediately shift into third at @ 17 mph. It won't stay in 2nd like it should. It only does this during this shift. The 1-2 and 3-4 shifts are like they should be. Under heavy throttle it will stay in 2nd like it should. The funny thing about the tranny is that it will have a very firm shift under moderate throttle but under heavy throttle the shift is so light that it seems to slip into the next gear. By heavy throttle I mean @ 3-5 psi of boost and maybe half throttle. It has the wide Red Eagle band, 200 servo, Bruce's shift kit and a "stock replacement" convertor from Aamco ( who did the rebuild by the way ). Under moderate throttle the shifts will almost bark 2nd and are very nice on the other shifts too. If turning while doing this the tranny will bark 2nd. I'm hoping to get a performance valve body put in to make it shift firmer but haven't found one at a reasonable price yet. I would also like a pressure test done but after spending 2 grand with Aamco I'll have to wait to have further work done. I thought I'd ask about blocking the accumulators in hopes that the heavy throttle shifts will be made firmer and not burn up yet another tranny.