Order Sheet Tranny Question

[CaliDude76]

I was under my hood today and was looking at the build tag on my wheel well.

I noticed that it said 4 speed auto trans. Is that three forward plus one reverse, or did my truck originally come with an O/D transmission that the P.O. swapped for a th350?

The gear selector does read "P R N D 2 1"

Just curious about this... my dad did say that years ago, a mechanic he took it to, had swore up and down that the truck was suppose to have had O/D, when he went to smog it, and have it serviced.

(Pops said the dude was crazy...)

 

[HotRodPC]

Yes sir. That truck would have originally had a 700r4. Someone has swapped it out. Obviously a done right conversion since the selector is also correct.

Your positive that is the correct sticker for your truck? The VIN # should be at the top of the sticker. If it matches your VIN, then yes its the right sticker too.

 

[HotRodPC]

BTW, I do beleive it was 82 when Squares started coming with 700r4's. Some did some didn't, but by 84 it was pretty much standard equipment for a half ton. 3/4 tons still had the 3 speed since the 700r4 wasn't strong enough rated for the C20/2500 and above. Finally when GM made a strong enough OD trans for the C20/2500 and above trucks,it was he 4L80-E, electronic transmisson. I do believe it was thru 90 the bigger trucks used the Th400, then in 91 the 4L80-E evolved. I might be a year or 2 off on that, but that's how they came about.

 

[CaliDude76]

Yes sir. That truck would have originally had a 700r4. Someone has swapped it out. Obviously a done right conversion since the selector is also correct.

Your positive that is the correct sticker for your truck? The VIN # should be at the top of the sticker. If it matches your VIN, then yes its the right sticker too.

Yeah, all the VIN#'s do match, so I guess that old mechanic stands corrected.

Very interesting, I'm wondering why someone would swap all that out. My dad bought the truck from a dealership back in 1989, and it was only 5 years old with 70k on it when he brought it home.

 

[HotRodPC]

Honstly, the first 700r4's were complete junk. Plagued with problems. I would not be supriszed if that is why someone got rid of it. I wouldn't even be afraid to say that GM may have converted it back to h350 jus to please a customer if they had an extened warranty or something of that nature.

 

[HotRodPC]

On another note, looking at your sticker, you have 3.08 rear gears. I woudln't even consider changing it back to 700r4 unless you wanted to change the rear gear to 3.73 or 4.11. Yes I did say 4.11 instead of 4.10. In the 10 and 12 bolt rear ends the ratio is 4.11 instead of 4.10. Not even a difference worth making issue of though. Many hear of the 4.56 ratio, Fords actually run a 4.57 ratio.

 

[bucket]

My '84 doesn't have O/D, it's just a 3 speed auto. It's not even a TH350, it's still the original TH200 or whatever it was called. I think you are lucky to have the TH350

 

[Swims350]

an original th250 or something? you sure it's not something somebody swapped in?

Our 84 c10 had a th350c and was that way stock I'd guess because our cluster is 3 spd. too, I also think the SPID had 3 spd. but can't remember it's long gone now.

 

[RetroC10Sport]

Yeah, 350, 400 and 700 were the only options in 1984.

 

[HotRodPC]

200 and 250 were NEVER used in trucks as OEM. Very weak transmisisons. At the biggest, the 200 was used in like an El Camino or Regal. 250 was used in smaller cars like 4 cyl Monzas.

 

[HotRodPC]

Yeah, 350, 400 and 700 were the only options in 1984.

I'm actually suprised to hear the Th350 was still used in 84's. I wonder if it was just for the 6 cylinders or was it the base trans in the v8 1/2 tons and the OD trans was an option. Somewhere along the mid 80's 700r4 became the standard trans. Just not sure what year.

 

[dhamp]

On another note, looking at your sticker, you have 3.08 rear gears. I woudln't even consider changing it back to 700r4 unless you wanted to change the rear gear to 3.73 or 4.11. Yes I did say 4.11 instead of 4.10. In the 10 and 12 bolt rear ends the ratio is 4.11 instead of 4.10. Not even a difference worth making issue of though. Many hear of the 4.56 ratio, Fords actually run a 4.57 ratio.

HRPC, I read somewhere that the 2.73s and 3.08s used a different carrier than the rest (numerically higher). I believe it was when I was researching lockers. Know anything about that??

 

[HotRodPC]

I'd have to check and make sure, but on the 8.5 inch 10 bolt, I do beleive the 2.73 and up numerically use the same carrier.

If you have 12 bolt, then is 3.73 and up numerically meaning lower gear. So 3.73 carrier should work for 4.11 and 4.56 etc. Then the 3.42 and down to 2.73.

If your not wanting to change gear and just go with a locker, go with Richmond Powertrax Lock Right unit. Its just a spider gear replacement system. Take out the spiders and install this unit, now you'd have a locker and that will work on any gear ratios. Only thing you need to know for sure is what your spline count is on your axles so you can get the right outer gears.

 

[skysurfer]

Honstly, the first 700r4's were complete junk. Plagued with problems.

Back around '87 I had an '84 Scottsdale with the 700r4. At the time, a mechanic friend told me to never tow anything with it until it was rebuilt with upgraded parts. I never rebuilt it because I didn't have anything to tow, and eventually I sold the truck with the trans still working fine.

My roommate's '85 was another story. He owned a 28 ft. boat and a 30 ft trailer. The 700r4 blew up quick. Even though he wasn't the original owner, he called GM Customer Service and complained. At the time, GM was trying to squash bad publicity due to the number of early production 700r4 failures so they had the local dealer install a complete new transmission free of charge.

 

[CaliDude76]

My '84 doesn't have O/D, it's just a 3 speed auto. It's not even a TH350, it's still the original TH200 or whatever it was called. I think you are lucky to have the TH350

Thanks... we seriously haven't had a lick of trouble with that tranny in the 22 years we've had the truck, until just a few weeks ago when it just stopped working altogether.

The tranny itself had to have at least 400k miles on her... so not a bad haul.

The dude that re-build my tranny said it was good and worn through. We took it as far as she would go, and then some!