80schild

iTrader: (5)

It's been awhile since I've posted here, but I've been tinkering with my GTA again lately.

Anyways, I had my transmission replaced with a rebuilt one from a '92 Chevy full size van. Ever since then, it upshifts too soon. 1-2, and 2-3 are fine, but it only stays in 3rd gear for a second before shifting into overdrive. Cruising at 60mph, if I floor it, it'll kick down into 3rd for a second, and then right back into overdrive.

The tv cable is adjusted properly going by procedure. So I'm thinking now maybe it's the governor. Would the governor in a 700r4 from a Chevy van be the same as my stock one?

sofakingdom

iTrader: (1)

No. Different springs & weights, resulting in very different behavior.

Get a "Corvette" one. Widely available from most any transmission supply place. The ones in TPI and L69 F bodies were the same as that one. The "Corvette" servo might also be a worthwhile upgrade, also widely available and cheeeeeeeep.

80schild

iTrader: (5)

thanks for the confirmation. I had that transmission replaced several years ago and have always felt like something was wrong. It's very sluggish unless I manually keep overdrive from engaging too soon. It was rebuilt to go in an older man's Chevy van, and while that was happening the man died so it was never put into it.

It looks fairly simple to swap out just from watching some videos on YouTube.

sofakingdom

iTrader: (1)

Yes in fact it is. Main issue will likely be, it's kinda long, and has to come out a ways to clear everything, so you might have interference from the exhaust, floor pan, etc. Piece o cake other than that.

The servo is similar. What upgrading that will do, is improve shifts into and out of 2nd and 4th. Most especially into those gears.

Fast355

iTrader: (2)

The real problem is it is not just the governor. The whole valve body calibration is different. It is doubtful the governor alone will change the shift points in a big positive way.

80schild

iTrader: (5)

I ordered a new Sonnax 730 that should be here in a few days. Hopefully it'll be some improvement. It's really just the 3 to 4 shift that comes on too early. I've read somewhere that the 700r4 isn't supposed to shift into 4th at WOT, but that's not the case with mine.

Fast355

iTrader: (2)

Always heard that too, but I had 2 units that would. The two van units I had in vans would also hold 4th at WOT if you are running 70+ mph. Always had to pull the shifter down to 3rd to get passing gear at 70+.

BHR

governor is matched with valve body the best combo would be from a 93 f body as it still was cable and had WOT shifts 56-5800 and hold the part throttle shifts longer any case you can still alter your shifts to get very close to what it was stock or what your trying to do

If i had to guess if your car is original 350 TPI it should have the skeleton type governor this governor is very open and had light triangle weights to get 5200 rpm wide open shifts

you need to get a governor adjustment kit if you want to tune the shifts and may need two kits if real particular with the tunning, the springs affect part throttle shifts, the inner weights affect WOT, the outer weights i assume is what is more critical to being matched with the valve body you may be able to get away with just removing the lightest spring on your current govenor

vinny R

Did you get this installed yet? Did it make a difference?

80schild

iTrader: (5)

not yet. Hoping to get a day off work soon to get it done.

80schild

iTrader: (5)

Well I got the Sonnax 730 put in yesterday and there's not a huge difference. WOT it shifts from 2nd to 3rd at about 3300 rpm, and about the same from 3rd to 4th. Cruising at 55 mph, if I floor it, it'll kick down into 3rd, but not 2nd.

1st to 2nd shift seems fine.

DynoDave43

iTrader: (11)

If you hold the trans in 2nd, what rpm are you turning at 55mph? Seems like maybe a downshift to third, and not second at that speed is perhaps correct.

BHR

Because you have a van 700r4, the valve body is different you need a recalibration kit in the mean time try just removing the softest spring from that governor, a f body 700r4 with 3.27 gears should kick down to 2nd at 55mph

https://www.ebay.com/itm/20341986897...51c4efdaf3409e

80schild

iTrader: (5)

I did order that yesterday.

BHR

I would start with the springs (bc it easier then changing the pin to change the weight) removing the lightest one just to see if it will fix the low 2-3 WOT shift and 3-2 kick down if the 1-2 WOT shift is good at 5-5500 rpm then lighting up the inner weights will only move that even higher

80schild

iTrader: (5)

I don't think the WOT 1-2 shift goes quite that high, maybe around 4k.

Honestly I'm just trying to get it like it would have been stock. I think I read somewhere that the stock shift points were around 4800. Does that sound right? I can't remember what it was with the original transmission since it was changed awhile back.

TTOP350

iTrader: (8)

Sounds like you need to rebuild the stock trans and put it back in.

80schild

iTrader: (5)

It's long gone unfortunately. I was told at the time that they were the same, so I didn't question it. The shop that did the work is actually very reputable.

Fast355

iTrader: (2)

With a 3.08 or 3.42 gear the stock van trans would kickdown to 2nd at 55 mph. The 92 G20 I had with 3.42s would run about 65-70 before it upshifted to 3rd. Even the diesel version upshifts at ~4K with a properly adjusted and functioning TV system. I say system because the 700r4s TV spring that moves the TV plunger is bad about getting weak and cause SSS or short spring syndrome. I would follow the Bowtie Overdrives TV101 article, make sure the TV system is correct prior to attempting any more calibration changes because it seems to not even be shifting like it would in a stock van.

http://www.bowtieoverdrives.com/Instructions/TV_101-1.pdf

80schild

iTrader: (5)

Would a rebuilt transmission usually have a new spring? This transmission has less than 2k miles on it since rebuild. Embarrassed to say that was about 11 years ago. I just haven't driven it very much as I've had other things going on.

I did have someone sit in the car today and hold the pedal to the floor while I checked the cable at the throttle. There was very little extra movement and the cable seemed plenty tight.

sofakingdom

iTrader: (1)

​​​​​​​Probably not.

BHR

All the 350 TPI's with auto I drove would WOT shift around 5000-5200 for 1-2 and 2-3 shifts the 2-3 is usually a few hundred more than the 1-2, the 305 TPI and TBI would shift at 4800, when calibrating I would aim to get them below 5500 and above 5000

Also one thing not mentioned is check for actual MPH and RPM the gauges are usually off going off mph your WOT shift should be at 35mph and 2-3 should be close to 75

80schild

iTrader: (5)

Update:

I changed the weights and springs using the Superior kit and it definitely shifts at a higher RPM now. I think I overdone it just a bit though, so I'm going to bump up one of the springs and try again.

exiled350

iTrader: (1)

What weights and springs did you use and where was it shifting that was too high? I am in a similar situation where it shifts way too early and am having very little luck finding anything other than keep changing till you find what you like. As I am sure most of us are aware that's not as easy as it sounds.

80schild

iTrader: (5)

I think I've got it close to stock now which is what I was aiming for. WOT 1-2 shift is at 5k, and 2-3 shift is about 4,200. Driving at 55 if I floor it, it kicks down to 3rd, if I'm going 45 and floor it it'll kick down into 2nd.

I'm using one original weight, with the 'E' weight (not shown) from the kit. I'm also using the orange and green springs.

Originally I tried using 'D' plus 'E' with orange and purple springs. It was WAY too much. I didn't even think it would ever get out of 1st gear even with light throttle.

80schild

iTrader: (5)

This is the other weight I'm using that was already in the governor. It has an E stamped on it, but it's definitely nothing like the E from the kit.