3/4 accumulator spring
Thread Starter
TECH Apprentice
Joined: May 2010
Posts: 361
Likes: 0
3/4 accumulator spring When I tore down my trans and VB there wasn't a spring under the plate with the 3/4 accumulator. What is the purpose of this? It has the alum 3/4 and plastic 1/2 .
And no I didn't mis place it lol
And no I didn't mis place it lol
Moderator
Joined: Aug 2010
Posts: 7,323
Likes: 529
From: Ann Arbor, MI
The primary "ingredient" of the 1-2 and 3-4 accumulators is pressurized fluid between the separator plate and the piston. Similar to a shock absorber. The pressure of the accumulator fluid is set by the Accumulator Bushing/Valve spring in the valve body. (This is the spring in Step 4, Page 2 of the Transgo HD2 kit).
The accumulator springs "modify" the action of the accumulators. Putting spring(s) on the side of the piston away from the separator plate causes faster/firmer shifts.
For the 3-4 accumulator some 700R4 and early 4L60E models had the spring on the separator plate side of the piston; I think this would soften the shift. Later models and shift kits, e.g. the HD2, put the spring on the piston side away from the separator plate.
So, a missing spring would give you a relatively soft 3->4 shift. For a firmer shift assemble it by inserting the spring into the case, then the piston, then the separator plate, exactly as in the HD2 instructions.
The accumulator springs "modify" the action of the accumulators. Putting spring(s) on the side of the piston away from the separator plate causes faster/firmer shifts.
For the 3-4 accumulator some 700R4 and early 4L60E models had the spring on the separator plate side of the piston; I think this would soften the shift. Later models and shift kits, e.g. the HD2, put the spring on the piston side away from the separator plate.
So, a missing spring would give you a relatively soft 3->4 shift. For a firmer shift assemble it by inserting the spring into the case, then the piston, then the separator plate, exactly as in the HD2 instructions.
Staging Lane
Joined: May 2013
Posts: 68
Likes: 0
From: LA.
The primary "ingredient" of the 1-2 and 3-4 accumulators is pressurized fluid between the separator plate and the piston. Similar to a shock absorber. The pressure of the accumulator fluid is set by the Accumulator Bushing/Valve spring in the valve body. (This is the spring in Step 4, Page 2 of the Transgo HD2 kit).
The accumulator springs "modify" the action of the accumulators. Putting spring(s) on the side of the piston away from the separator plate causes faster/firmer shifts.
For the 3-4 accumulator some 700R4 and early 4L60E models had the spring on the separator plate side of the piston; I think this would soften the shift. Later models and shift kits, e.g. the HD2, put the spring on the piston side away from the separator plate.
So, a missing spring would give you a relatively soft 3->4 shift. For a firmer shift assemble it by inserting the spring into the case, then the piston, then the separator plate, exactly as in the HD2 instructions.
The accumulator springs "modify" the action of the accumulators. Putting spring(s) on the side of the piston away from the separator plate causes faster/firmer shifts.
For the 3-4 accumulator some 700R4 and early 4L60E models had the spring on the separator plate side of the piston; I think this would soften the shift. Later models and shift kits, e.g. the HD2, put the spring on the piston side away from the separator plate.
So, a missing spring would give you a relatively soft 3->4 shift. For a firmer shift assemble it by inserting the spring into the case, then the piston, then the separator plate, exactly as in the HD2 instructions.
Thread Starter
TECH Apprentice
Joined: May 2010
Posts: 361
Likes: 0
When I bought the car 5 yrs ago the guy I bought it from said "I went threw a couple 4l60e's in a short period of time once and my trans builder told me that hard wot shifts into 4th is y I keep braking them and said that I need to stop letting it shift into 4th so hard"
Is there any truth to this? Could this be why there is no spring for happy medium between spring on case side vs plate side?
Thanks
Is there any truth to this? Could this be why there is no spring for happy medium between spring on case side vs plate side?
Thanks
Thread Starter
TECH Apprentice
Joined: May 2010
Posts: 361
Likes: 0
Nothing since I've owned it, I was quoting the guy I bought it from 5 yrs ago I don't remember what he said he kept braking but I want to say it was a snap ring for some reason .
But recently the torque converter came apart, while I was tearing down the trans to check things out for damage and debris I noticed that there was no spring with the accumulator under the plate.
So I was wondering y someone would leave it out?
But recently the torque converter came apart, while I was tearing down the trans to check things out for damage and debris I noticed that there was no spring with the accumulator under the plate.
So I was wondering y someone would leave it out?
Moderator
Joined: Aug 2010
Posts: 7,323
Likes: 529
From: Ann Arbor, MI
Accumulator springs do occasionally break; not uncommon in the 1-2 accumulator as there will be many WOT shifts and WOT maxes out line pressure which causes faster shifts.
WOT 3->4 shifts are uncommon as, depending upon rear ratio, it would be between 120 and 150mph.
However, some "hack" mechanics significantly increase line pressure at all times by excessively adjusting the set-screw on the Pressure Control Solenoid (PCS). While some people might like the resulting extra-firm shifts, it is very hard on the trans, u-joints and rest of the drivetrain.
The next time the valve body is off, I would put the 3-4 accumulator spring back in, but I wouldn't remove the valve body just to do that.
WOT 3->4 shifts are uncommon as, depending upon rear ratio, it would be between 120 and 150mph.
However, some "hack" mechanics significantly increase line pressure at all times by excessively adjusting the set-screw on the Pressure Control Solenoid (PCS). While some people might like the resulting extra-firm shifts, it is very hard on the trans, u-joints and rest of the drivetrain.
The next time the valve body is off, I would put the 3-4 accumulator spring back in, but I wouldn't remove the valve body just to do that.
Trending Topics
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo Thread Starter
TECH Apprentice
Joined: May 2010
Posts: 361
Likes: 0
Order a kit from probuilt last nite, it aways nice to have guys like Dana (PBA) around for incite and just good ol' conversation. He's forgoten more about this stuff than most of us will ever know about it.
Thanks Dana, great talking to you
Thanks Dana, great talking to you
