Super T10 + DNE - 4+3 trans - issues - just useless info
 

59 GMC 100 ---------- My spare 4+3 is an 85 just like the one in my 85 vette. I did get info (good or bad) from another forum that the tv cable does just soften the shift but is not necessary for use of the trans - it does not function like a 700R4. It was suggested to put a slight stationary pull on cable then plug.

I bought my 85 4+3 in 1997 - still have and drive it. I maintain it and it performs as intended. I bought the spare from a wrecked 85 in 1998 and properly stored it for later use - 2020 - in something.

About 3 - 5 months ago, I put the spare 4+3 in my 59 GMC 100. I dumped the fluid and changed the filter about 8 years earlier. All looked well. Added ATF , my OD did not work in fact once in second or above and turning on OD -- it skidded the rear tires. The transmission would lock.

Finding out info on these DNE's is scarce. Soooooo, I just drove it in direct drive for 3 months unhooking the solenoid so that I would not accidently engage it. My thinking was that the direct drive clutches were not releasing when the OD clutches were engaged and driving it in direct drive may loosen things up.

I was right maybe -- wow --- yesterday I hooked the solenoid back up and went for a drive. After shifting to second I clutched and engaged the OD, it slowed down then it finally engaged the OD. Now it shifts in and out of OD fine.

I will admit the shift is a little stiffer behind the 250 six in my 59 GMC ---- my 85 vette is a little softer behind the L98.

With the help of this forum I just rebuilt my first 350 TH and now have a better understanding of some auto trans. With a video and instructions I would attempt to overhaul a DNE if needed.

The 4+3 Super T10 is a wide ratio. The vette runs a 3.07 (autos were 2.73) rear gears with 255/60x15 -works well. The 59 GMC has 3.73's with 31 inch tires. First gear with a 250 six is a little tall for it - the rest work fine. Of course now I am pulling a working 4+3 to finish making my 59 GMC Fleet a 4wd. But at least I know it works.

dennis

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Re: Super T10 + DNE - 4+3 trans - issues - just useless info
 

Sounds like a fun ride as is. I always wanted to see what was in one of those overdrives. I was looking for one when I came across my T56 combo.

Re: Super T10 + DNE - 4+3 trans - issues - just useless info
 

I wanted to get one of those tranny's for a car that I had, but was told there not very strong. But T-10s supposed to be strong tranny's. Don't matter now, sold the car lol.

Re: Super T10 + DNE - 4+3 trans - issues - just useless info
 

I guess Doug Nash did a couple of upgrades in 86 but I read they are rated to about 350 HP and can break like anything else. My 85 vette owners manual gives no rules on shifting. Like gear vender they do not want an upshift until 2nd gear because of low pump pressure on the clutches. The pump as I understand runs off the rear axle turning the driveshaft back to the OD. I think the GV operates the same way but is far more capable.

Some like them and some don't -- I do in my 85 vette and would have in the gmc.

I can have the trans in neutral, clutched and it will still upshift if in or past 2nd gear moving. OD to direct drive again is solenoid off allowing pressure off the OD clutches and spring pressure re-engaging direct drive clutches. (Layman)