700R4 wont shift into 3rd

[Subourbon]

Hey guys,

1982 k20 suburban with 6 2 diesel and 700r4 trans 4x4.

So yesterday went out, on a road that'd about 50mph drove there fine, no issues.
On the way back, 1st to 2nd, shifts a bit hard but that's been the case since i got the truck.

Coming up to shift into 3rd just nopes out.
Almost seems like it drops into neutral, because even when I left the speed come down so it can come back into 2nd I'd just rev the guts out of the engine. So I'd shift into neutral back to drive and bum around in 1st n 2nd all the way home sometimes it would come back down to 2nd it seems, other times shift to neutral n back to D to get going
(Sadly I don't know what rpms the gears shift up or down, I don't have a tach on the dash).

Once home, I adjusted the Throttle valve (TV) cable in the TV cable for dummies way, press the button and floor the loud pedal and it should adjust.

The adjustment worked before, bout 2 years ago, I changed the glow plug controller which is threaded through the TV cable bracket and into the bloc, the tv cable clups into that bracket, under the fuel lines formthe injecrion pump and connects tonthe throttle bracket, (not sure if itd called thar. Anyway) Upon completing that job I shifted into D and went nowhere. And that's where I found out about the button and floor the throttle pedal to adjust. And it worked.

So back to the most recent adjustment, it revved the guts out of 1st before banging in 2nd, and eventually got 3rd but man engine was screaming, didn't like any of that prior to this whole story, it would shift between all gear easily.

Checked the fluid level while hot in park engine running I'm at the top of the hash marks, so I believe I'm good for that.

The trans is newish when I bought the truck the guy had just replaced it and having a look underneath you could see the trans was far cleaner than the rest of the undercarriage. Does that guarantee its new coz it's clean? No but why would he just clean a transmission, the guy aas really honest bout everything else, said the brakes were crap, and they were so... lol.. it shifted just fine until literally yesterday.

Do TV cable just poop the bed like that? Or is there something more sinister happening inside the trans.

I know nothing about transmission I watch the videos and the valve body taken apart blow my mind as to how it works.

The TV cable adjustment worked before, I wish I remembered how tight it was when I adjusted it back when I did the glow plug controller job, but I don't remember.

Shift into reverse just fine. Yesterday 1st to 2nd was ok i the way home, but since adjusting again it seems to Rev more in 1st....

Any insight is welcome. There's videos online bout governors this and that but I've had good luck on this forum with a lot of knowledge being shared, so again, thanks.

If I wasn't clear on something let me know, I'll elaborate. I thi k I'll do some.tv cable shopping maybe that's the cheapest thing to try now.

Also, it had 87000 km's (canada) when I got it and I'm up to 95000 so maybe a transmission fluid change too? But color and level were both fine, so I dunno.

 

[89Suburban]

@NickTransmissions

 

[Subourbon]

I might also be a moron. I know it's a 4 speed which is why i say it's a 700r4 and not a th400 which Google says it's a 3 speed...
I've got
Park
Reverse
Neutral
D (with a circle around it, which I believe is overdrive, which is what I drive around with.
D -no circle
2
1
And like I said4x4 with transfer case for 2 high 4 low and 4 high obviously.

 

[NickTransmissions]

I might also be a moron. I know it's a 4 speed which is why i say it's a 700r4 and not a th400 which Google says it's a 3 speed...
I've got
Park
Reverse
Neutral
D (with a circle around it, which I believe is overdrive, which is what I drive around with.
D -no circle
2
1
And like I said4x4 with transfer case for 2 high 4 low and 4 high obviously.

Neutral condition at the 2-3 shift is burnt 3-4 clutch pack. Time to pull it for overhaul. You can always drop the pan to be sure but if it went from shifting through all its gears normally to neutral in third (assuming you still have 1st and 2nd and no tv cable issues), trans is done.

Check out my Youtube channel for the 700R4 playlist - has step by step tear down and rebuild videos. Let me know if you need any help on parts selection or procedures.

 

[Subourbon]

Damn. Well that's bad news bears. Errr...
Any symptoms of that or does it just go like that.

And earlier today it did eventually shift into 3rd but while reving the hell out of it. So I guess that doesn't change much. Tv cable adjustment needs fine tuning because 1st to 2nd is pretty rough.

Tha ks nick I'll check out the YouTube channel. I think it'll be a shop job, I'm not too well set up here for a trans overhaul. No garage. Lol

 

[bucket]

Damn. Well that's bad news bears. Errr...
Any symptoms of that or does it just go like that.

And earlier today it did eventually shift into 3rd but while reving the hell out of it. So I guess that doesn't change much. Tv cable adjustment needs fine tuning because 1st to 2nd is pretty rough.

Tha ks nick I'll check out the YouTube channel. I think it'll be a shop job, I'm not too well set up here for a trans overhaul. No garage. Lol

They can just go like that. I remember riding with a buddy in his '91 K5, it was shifting perfectly fine. We drove past a house that had a pair or free slotted mags out at the end of their drive, so we stopped to get them. We loaded up the wheels, drove off and... suddenly everything after 2nd gear was a neutral. Just like that, lol.

But on the other hand, I once killed a 700r4 in my Camaro and installed a used one that was supposed to be "a real good one that was built" but it was not. It slipped badly on the 2-3 shift, so I just let off the throttle for every 2-3 shift. I drove it for about a year like that and it never failed completely.

 

[Subourbon]

@bucket,

Yeah that's why I was shocked by nicks response, to drop it and overhaul. I replaced my rad (leaking) and didn't top off my trans fluid after having lost whatever was left in the old rad and line when I un plugged everything and noticed reverse and drive was complaining. Topped it off to the proper level and, fine.
But yeah, I guess it just goes like that then eh.
Damn, what a piss off. To be honest though, despite the 6 2 diesel being gutless and hated on, it's f-ing reliable. And I haven't had much difficulty with it.
Brakes, rad and glow plug controller in 4 years of owning it. So not bad.

 

[squaredeal91]

I've had em go like that. I usually helped it along by being bad to it and then it feels like it shifts but won't hold at all. Just like neutral.

 

[GTP51]

Same happened to me, 12, then 0 as previously mentioned time for a rebuild unfortunately

 

[gmbellew]

I'd try adjusting the TV cable 1 more time. or at least manipulating the throttle at the carb instead of using the gas pedal to set the tension. I believe the manual calls for it to be adjusted at the carb/throttle body and not by the gas pedal.

and check the fluid again.

if all that checks out and still an issue. I'd suspect a rebuild is in order.

 

[Subourbon]

Unfortunately it's already at the shop and has been for some time. So can't adjust anything.
Shop guy said yeah trans is toast. The rebuild is quick tedious coz of lack of parts. I'm shuddering at the thought of the bill. But it is what it is...


On a completely separate note, with winter coming I have another question.

The alternator seems "weak". Let me explain, in the winter when I have the heat on, I'll be going along, no issues, then pull up to a stop sign or red light. And set off again, and the belt squeals like crazy, but will stop if I turn my heat off.

I know what you'll say, tension, but it's fine engines warms and, it does it in the summer too. This is bone stock, no ac only add on are two off road lights innthe front not huge light bars, and when I turn those on at night itll do that squeaking nonsense... Also, when I jumped a dead battery on another car I could it squeak squeak squeak at idle. Like, when i add a load the alternator can't manage it.

So is it an alternator on its way out? If can't seem to handle its own equipment like a simple blower motor.

I despise that noise, it changes my batteries just fine but with the heater on and the AUX lights installed by the other owner it can't handle it. And I know there are more trucks out there with more power or amperage hungry mods than mine out there so, what do I need to do?