WSteve6

I was just wondering what people think of a 4L80E vs. a TH400 and the Gear Vendors overdrive? Basically I'm trying to figure out which is the more bullet proof trans for the cheapest cost. Anyone know approximately how much each will cost when all is said and done if one would be "better" than the other, meaning will one hold up longer or should they be about the same?

john kilgore

the 4L80 will be cheaper in the long run. you can get a stall tc and still have lock up and you still have 25% od good luck. the controller l use lets you change the pressure, shift feel, shift timing etc.

SmokingWS6

iTrader: (1)

Also, 1st - 3rd gear in a 4L80 uses all the same aftermarket parts as a th400.

PRAY HRD

iTrader: (119)

hey man.......

the down side is there are no good/reliable trans brakes for the 4l80's yet from what i've heard. so if you are wanting one, look into the GV, or better yet IMO, the V2OD unit. it's nearly $1000 less, and can take all the abuse you'll likely ever throw at it. it's been tested to 1000+hp so far with no problems when run indirect, the same way the GV is measured. they are made by US Gear, the same company that Moser uses exclusively from what i understand. with that being said, they are a reputable company and the customer service is top notch. i had bought one for my vert. SS, but thought it did not fit due to where i measured it. however, if a GV can fit in our cars, so can this as it's nearly identical in size. take a look at the pic. they also have a cable operated unit too that's the same price, and either a .80 od gear or a .70 gear too. hope that helps your decision some. btw, either a GV or V2OD can be used with a trans brake when they are not engaged.

later,
Dave

btw....it weighs 50lbs. and takes an avg. of 1% hp to turn. i don't know the difference in weight of a 4l80 or if it takes more power to turn than just a th400. but even at 800hp, you'll only lose 8rwhp and have O.D. and a trans brake will more than make up that power loss off the line with the much harder launch.

jxaxsxoxn

iTrader: (2)

I know hardparts for 4L80E's are way more expensive.
I bought a 1998 trans for my truck and it had some major wear in it with only 60,000 miles on it. I had to put $200 just for hard parts like the forward clutch housing, the center support bushing was worn with about 1/16" clearance in it. The clutches were still all good.

On the other hand I've got ahold of th400's with unknown miles, worn out clutch frictions and have just put a $120 rebuild in them.

Patrick G

iTrader: (14)

T400s don't require electronic control which is a plus. On the downside, getting a T400 with a lock-up clutch is a very expensive proposition (they exist in the aftermarket BTW). Big question is, do you want a lock-up clutch? If so, the 4L80E is probably the better choice.

James B.

iTrader: (1)

GV can shift WOT at any speed, the V2OD cannot.

One thing to note about how it shifts though is that the GV uses an on/off solenoid. There is no line pressure control that can be based off throttle posistion or any of that. It engages and disengages very firmly, the firmness you FEEL will be determined by how much throttle you are putting through it at the time. At low throttle the tprque converter is more lose and with more throttle the converter gets tighter. The GV controller will always unlock the TCC (if you have one) to shift itself no matter what speed or gear the trans is in. These units cannot be used to split gears on a sprint. There are delays with engagement and with disengagement that are impossible to coordinate with trans shifting.

Given the choice of TH400+GV and 4L80-E, the 4L80-E has the advantage. It can be programmed. Shift points, shift firmness, TCC lockup, downshift heuristics, Line pressure vs. TPS, etc... the list of stuff you have control of goes on and on. Nice and soft around town, very firm and solid WOT = NO PROBLEM. (Just try to manually calibrate a valvebody on a non-electronic trans to give you that.) I figure if you're going to put something as heavy and parasitic as an automatic transmission in your drive train, the damn thing should shift itself and do it better than you could. Programmed right, the 4L80-E can and DOES.

PRAY HRD

iTrader: (119)

so James.....

in essence, isn't what you're saying then is that the GV unit is basically OFF when your going down the quarter? so when racing, there is no realized benefit to having a GV over a V2OD if i'm understanding correctly. and yes, the 4l80E would be the best choice if this is still your everyday car, or close to it. but in my case, i'm going to put maybe 2500-3500 miles a year on the car, and wont do without a t-brake. so the 4l80E is out of the question. this is a good topic, and i've been waiting for one of these for a while now.

Dave

James B.

iTrader: (1)

Yes - exactly. The GV "could" be engaged going down the quarter, but getting it to hit at the right RPM is hit and miss, and it would only be useful if your trans has run out of gear. For example, if you had a TH400 and 4.88's out back you would be running out of gear probably around 110 or something depending on redline, tire size, etc.. If you could get the GV to engage just before the motor redlines you'd get a lot more MPH to work with. Going down the track you only get one shot though, it's too slow to do more and really too inconsistent to be practical. You would NEVER want to try disengaging at WOT because if you're already at the top of the gear with the OD engaged, shutting down would push the motor way past the RPM point it takes to blow apart. Also, engaging it at 100+MPH and WOT is absolutely VIOLENT. I've done it and could swear the truck jumped off the ground. If you put one of these things on your car and are seeking consistent drag runs, the best thing to do would be to set up the rear end like the GV wasn't even there and don't use it. It's great for highways but has limited practicality on the strip. (I run double OD on the highway with the 4L80-E and GV, works great but I do have some SERIOUS driveshaft RPMs!)

PRAY HRD

iTrader: (119)

ok, so i did understood correctly. so if you don't think it's wise after your experience to shift above 100mph, than that is no longer a benefit to buying one for that purpose. so why would you go GV vs V2OD then for around town/highway driving if you could save over $800? i paid $1435 for mine. can i ask what the going rate for GV's are now? i haven't looked into one for about 4 years now. with the optional 30% reduction in rpm's vs the 20 or 25% from a GV, and that's what you're looking for in an OD, fuel economy is superior with the V2OD and therefor makes my statement of it being better "IMO" earlier undeniable. right? because i remember GV advertising the abillity to split every gear as you shoot down the track, but you're speak to the contrary. don't get me wrong. i value your real world thoughts on this subject greatly. there is not a hint of sarchasm in my words.
oh, and exactly! with either one of these OD's, definately set your car up for the strip as though it was not even there, since you will not be using it anyway. this will enable you to run the t-brake and go through the th400's gears like any other car that does not have an OD. then, pack up and drive home with an OD setup and smile.... you're living the best of both worlds!

thanks,
Dave

PRAY HRD

iTrader: (119)

(I run double OD on the highway with the 4L80-E and GV, works great but I do have some SERIOUS driveshaft RPMs!)


curious. i don't have the time, nor the patience right now to figure out the mathematical equation to understand this comment on the D/S RPM's. shouldn't the OD reduce the speed at which it turns, as it does the engine and trans? that's something i've never thought about and any insight would be appreciated.

thanks,
Dave

James B.

iTrader: (1)

I guess it is a matter of preference really. The Gear Vendors overdrives 22% and there are no options for different ratios. It's a planetary setup with a sprag and cone-type clutches. You could go down the road switching it on and off if that amuses you. The unit can do it. The controller has a semi-automatic mode where it will engage at about 45MPH and automatically disengage at about 18. It's independant of transmission gear or throttle position. It's truly hands-off overdrive management.

Driveshaft RPM....
I have 29" tires and 4.56:1 gears.
29" tires do 11.59 RPM at 1 mph (88/(29pi/12))
take my average highway speed of 85, multiplied by tire factor os 11.59, and gear of 4.56 and it comes to 4492 RPM at the driveshaft! It doesn't matter what's in there for a transmission, transfer case, or an overdrive - that's what the driveshaft on my truck is doing at 85 no matter what. If I had a only a TH400 in there I would be seeing engine RPMs at 85mph even higher than that by a little bit in top gear since it can't lock the converter. It's scary to think I've had the truck up to the speed limiter of 128mph = 6764RPM for the driveshaft. I know that stock ones cannot do that.... With the 4L80-E OD gear ratio of 0.75:1 and the GV OD ratio of 0.78:1 combined with TCC lockup I can get those Engine RPMs down to 2628RPM at 85mph with this setup.

WSteve6

Very interesting guys. I would be using it as a daily driver primarily. Thus, it seems the best choice for me would be the 4L80E which is what I've been leaning towards. I like learning more about it though so I can just make a better educated choice. Plus its cool to learn how these things work and why.

MeanWS6

try finding someone local with a TH400/4l80e and make up your mind. I chose the Th400 w/o GV. I figured, I will drive it a season and if I really need OD I can always add it later.
I stopped by Speed Inc last night, my old 4l60e was pulled and the Th400 was going in.
You are more than welcome to swing by or meet up and I will let you take a TH400 behind a 408 stroker to get a feel for it.
Depends on the day of the week, but I am frequently in Vernon Hills, Elgin, Schaumburg area.

WSteve6

That definitely could be fun, driving your car. Do you drive your car in the winter? I work in Bannockburn so **** if your out in Vernon Hills during the day we could even meet up at lunch sometime.

I personally really want OD cause spining at like 3500 while only doing 55-60 on the highway isn't to my liking among other things.