Rhythmic vibration at certain speeds

How hard do you want it?

"This borium is a slick, gray stick that works well when applied using an acetylene torch."

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It's can't hold 60mph in overdrive (4th) on just a moderate incline. It won't hold in 3rd gear on a substantial highway incline. I just got used to speeding up before hills and letting it fall back to 40-45mph at the crest to keep it in overdrive. Top speed was maybe 90mph in 3rd.

It's only rated at 130hp, badly made torque converters in my opinion...

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Converter lock is done via oil pressure being switched to it by solenoid in the tranny. There is a throttle position switch (was on right side of my injector pump) somewhere on your carb/injector body that tracks throttle position. Take your foot off the gas it unlocks. It also goes through the brake pedal switch. Step on the brake, it unlocks. Another switch in tranny that won't allow it to lock till its in at least 2nd gear.

You probably need the wiring diagram to track it down effectively.

Don't I remember you installing a different intake/carb setup on this? Did you transfer over the throttle position sensor for it?

Dealership thought it would run hot without the torque locking up on long drives...

No I don't think I have it wrong. If you have a low numeric rear end

- say a 2.5:1 to get 1000 ft lb of torque at the rear axle you need

400 ft lb of input torque.

With a 4.11:1 rear end to get 1000 ft lb to the rear axle you need only 243 ft lb of input torque. The torque converter only sees the INPUT torque. In the case of the 6.2 liter Diesel - stock they output only 145hp and 275 ft lb of torque at 2000 RPM in about 1984.

Compare that to a gas engine - say a 305 small block that only makes

120? ft lb at 2000 - - up to 175 at 3000 and 225 at 3500.

Cruising at 2000 rpm in direct drive and hit the loud pedal the torque converter sees a LOT more torque out of the deisel - than it would see out of the 305 - and so will the rear end

With 4.11 gears the engine will be reving higher at a given road speed than with a 2.5:1 - and the deisel feeding the 2.11 will put a LOT more punishment on the drivetrain than the 305 would.

Connected to a 4.11 the 305 is reving high enough to provide a bit more torque so it punishes the drive train at closer to the same severity as the deisel.

The .7:1 overdrive of a 700R4 makes 1 3.08 gear into a 2.15 and a

4.11 into a 2.87 A 4.38 rear end behind a 700R4 runs like a 3.08 behind a 3 speed (direct drive high gear) trans.

The 3.55 in my 5 speed ranger thinks it is a 2.76 when the tranny is in 5th.

Is the TCC vac switch a 2 wire or 3 wire?. If 2 wire just connect a switch to it and extend the wires back to the cab. Turn it on at cruise and see if it locks. If it doesn't lock just check either wire on the switch for power. If you have power and nolock it's the converter. If you have no power it is a control ossue. If it works with the switch but not without it is a vac switch problem - or a vac sourse problem. With no (or inadequate) vac the switch will never tell the TC to lock

GM doesn't think so either which is why they used a ROLLER bearing -

- - -- - It DID make pulling axles and changing grease seals pretty simple though compared to using ball bearings. - and if they were not runlow on oil or half filled with water they DID last almost forever. The bearing contact surface was something like 10 times the contact surface of a ball bearing

Forgot which oil burner you were laking about, The 387 Detroit was pretty anemic, particularly in stock form - and the highway geare they put on them for fuel economy didn't help ANYTHING. They WERE part of the problem with the torque converters though. Steeper gears unload the converter making them last a lot longer.

Those things were "flatlanders"

On a gas truck it has a vac switch inplace of the throttle position switch. Most common problem with no lockup was a cracked vac hose IIRC.

An extra heavy duty tranny fluid converter is ALWAYS a good idea on a truck with an automatic - especially if it has a lockup converter that may or may not be locking optimally.

Yes I have the vacuum switch . I'm trying to figure out which wire "goes hot" when the converter is supposed to lock . I know for a fact it was working before the rebuild . The solenoid was bad , it's wired on the same fuse as the radio (odd , ennit?) and every time it would try to lock it'd blow the fuse and kill the radio . The trans has been rebuilt with a new solenoid and many other parts including a shift kit . I'll be checking that hose ... But not tomorrow . Tomorrow I'll be replacing the bearing on the other front wheel . Should be easier than the first , I've gotten some better press blocks now .

I don't know if the converter is a heavy duty unit , I do know it's been rebuilt . I needed to add .125" spacers between it and the flywheel to get proper pump drive engagement .

In this case the axle itself was the inner race . Those shafts y'all spray welded up probably carried an inner race as part of the bearing .

I didn't get to see the bearing , just the axle and the dude called it a needle bearing . I just knew that I'm not equipped to repair a hardened bearing surface properly .

Correction - that was supposed to read "extra heavy duty tranny fluid COOLER"!!!!!

The "race" portion of Chevy axles were what I've seen welded and reground - 1950-54 chevy cars, 1947 to '61 or '62 1/2 tons.

The one really good thing about that style if axle is it was unluiky some hamfisted mechanic would nick it with the torch trying to cut the inner race off - - -

I have an old (1957) lawn mower and an old toy "express" wagon that use headless nails as bearings running on about 3/8" rod for axles inside a peice of tubing as the wheel hub center. At that speed they don't need to be hard - Not saying YOU should have repaired the axle - a man needs to know his limits - heck "I" wouldn't have done it - but if it was un-obtainium I would have found someone who COULD - at least up until 10 years agp. Most of the guys I knew who COULD to that back then are dead already and the rest of them are likely to shaky or frail or blind to attempt it - the shops they worked in are long gone and the machinery may no longer exist. They used to do crankshafts and camshafts too - and nitride all kinds of parts (TuffTride) - still a place here in Kitchener that does that - Plasma nitriding.

That makes sense . All mine has is the one in the radiator . But then I'm not planning on using it to haul heavy loads or pull heavy trailers for a living though it may do both occasionally . This truck is a toy for me now - and I've been very up front about that to my wife . She crabs a bit about the money I'm spending on it ... but then if it wasn't the truck it'd be something else . Every once in a while I'll spend some on the guns to give her a different subject .

Get your ohm meter. Disconnect the plug from the vac switch. Check harness continuity to ground. Whichever one has ground continuity is the switched side - the other is the powered side - assuming the solenoid is grouinded through the harness. Ir does the switch GROUND the solenoid - with power supplied to the solenoid? That has a 4 wire connector on the tranny???

If it hasn't been screwed with get the factory wiring diagram and check wire colors.

Speaking of gone, there was a shop near here that could rebuild worn hydraulic cylinder shafts, IIRC it involved nitriding or hard chrome as appropriate. They were my source for short rod and tubing cutoffs as lathe stock. If a classic vehicle axle can't be replaced a hydraulic shop might be an alternative to an automotive one.

I had mine in for warranty head gasket leaking coolant three times. It was only like the second year the 6.2 was out, maybe first.

The torque converter on mine had 6 mounting pads to the transfer plate. Most 700R4 transmissions use a 3 pad plate hook-up from what I understand. Was recently talking to a knowledgeable neighbor about it and he said it sounded like the 400 turbo pad arrangement. When I had to replace it in the late 1980's the transmission shop had never seen anything like it before and they worked on lots of 700R4's. The recent repair for it was the same per the new owner. Transmission shop had never seen it before nor could they find a new replacement. Had it sent out to a place in Kansas? that rebuilt it and sent it back.

Not being able to look inside... we (tranny mechanic and me) thought it had broke a weld where one of the "fans" was fastened to a coupling hub. It slipped really bad but I could still move the truck by using low range in the transfer case. Would have really liked to see the failure, could better guess then why it had failed. It was maybe first year production for the 700R4 too. Lots of failure points still being determined🤷