So, it's time to dig out the old Burb.

[DickWells]

Our 95 Suburban 2500 - 6.5 has been put away for at least 6 years, minimum, and it ain't doin anybody any good just sitting there, so I cleared all the junk from around, and under it, and hooked the Bombardier Traxter to it and pulled it out into the sunlight. It's had a battery tender hooked up all this time, and a nearly full tank of fuel, and after at least 3 years since firing up, it lit off within five turns and ran! Really rough, for about 20 seconds, and white smoke poured out the back. It settled down to a nice idle after 30 seconds or so, and the smoke went away, too.

So, to get to the question at hand. Though we towed our trailer to the West Coast and back, twice, with few shifting issues, back when, the incidence of refusal to shift up at times was annoying, and, since it'll be driven by others besides myself, now, I want to do something about getting the 4L80E to get into the desired gear. Been looking at Transgo's "Stick Shift" reprogramming kit. Anyone have experience with this unit, or advice? I'm sure that installation is pretty straight-forward, so, not concerned there, just want to
hear the likes/dislikes information, etc. Oh! The reason that the thing had any issues with the transmission, is, that I put a mechanical pump into it, back about 04-05, as my profile indicates.

The Transgo has to be shifted manually for each gear, including lockup, so I don't see why they call it a reprogrammer, although I'm sure there are some electronic over rides going on. It needs vacuum for the vacuum modulator that comes with the kit, and the Suburban does have a vacuum pump (which works, far as I know). If not, I'll replace it, no problem.

I still love this old rig! Feels good to get in and get that "feel" again. Can't wait to change the fluids, get some new tires on it and hit the road.

Like to hear from anyone who has information on my latest project.
Thanks.
DW

[JohnC]

(Going out on a limb now...)

If it needs vacuum, I suspect the vacuum needs to be related to engine load. Unless you somehow modulate the vacuum from the pump based on throttle setting, it won't cut it.

If you could find a trans controller from a '93 Diesel...

[JeepSJ]

I'd go with John's suggestion and try to find the stand-alone factory trans controller. Alternately I hear the TCI EZ-TCU units are very easy to install and set up. A few guys are using them on 4L80E swaps into older trucks and they really like them.

[DickWells]

Thanks, guys.

John: The Transgo unit comes with a vacuum modulator. I've talked with one of their techs, and he didn't know that the 6.5 had a vacuum pump, but, given that it does, he said it would work well.

SJ: The TCI unit sounds good, too. Certainly lighter on the wallet than the thousand-dollar SA units, but the Transgo is less than $300. Will keep on researching. My throttle is strictly home made pedal, hooked up to an old mechanical cable out of an earlier 6.5. I have the old TPS off the E-pump, but, IIRC, the 4911 doesn't have a mounting point. Will check that out.

[DmaxMaverick]

None of the "E" (DS-4) pumps have a TPS (on the pump). Actually, they have nothing ON the pump, other than wires and pipes. It has no mechanical in/output (other than the shaft that turns off the cam). The EFI TPS is the APP module (pedal), which indicates to the ECM/TCM. The 4911, and all other MFI (DB-2/4) pumps accommodate a TPS or vacuum valve on the "throttle" shaft, opposite the throttle cable. The TPS is for the tranny controller used for the 4L60/80 "E" tranny, and the vacuum valve is for the previous model's TH400 tranny. The vacuum valve operates the vacuum modulator on the tranny (like TH350 and 400's of the past), which controls shift points and line pressure. If it doesn't have a vacuum valve on the IP, but has a vacuum modulator on the tranny, it's no wonder it doesn't shift properly, or at all.

That said, if all is set up properly, and it still doesn't shift, check the vacuum pump and related plumbing. The pump should produce 20"+ vacuum at idle. A new pump should produce 25-26". Less than 20" at idle is a failed vacuum pump or leaky plumbing.

[DickWells]

Thanks, DMAX. The transmission hasn't had anything done to it, so, no, there's no need for vacuum at the trans. (until now, if I add a manual kit to it). I expected, years ago (04, IIRC), that I'd have all kinds of shift problems. Turned out that wasn't the case, for a long time. We towed to the West Coast twice without much trouble, but the last Summer or two that we used it, here at home (we bought the Sierra in 06), the shifting became more erratic, refusing to shift up more frequently. Our son used it in 09-010 to tow out to central NY to a horse camp, and enjoyed the experience, but noted that he had to stop and let it reset more often. So, it's been put away for at least five years without hitting the road, and I don't intend to attempt it without installing something to mitigate a problem that's sure to be present.

Don't know how I got away with the throttle hookup that I had for so long. I was pretty pleased with it, overall. My throttle pedal has a roller under the plate, and more "throw" than the the original and is very easy to modulate. I remember that I used to lift the throttle when I wanted to shift and it felt a lot like using a manual. Guess that's why I'm leaning toward the Transgo unit, I still like to do my own shifting and still miss it.

Which reminds me. The info that I'm seeking involves the potential issues with extreme harshness with the Transgo. Will it feel really rough, or clunky, or noisy? Or, will I be able to make it shift fairly smoothly, just by lifting the throttle at shift-points? I don't mind something that feels "positive", but I don't want something that my DIL can't learn to drive. BTW, she's fine with a manual transmission, being a former school bus driver with that kind in it.

[DickWells]

It's back on the road! And, we're liking it. At this point, nothing's been done to the transmission and it's shifting very well, indeed. Just lift the the throttle when you want to shift up, or, if you really get "on it" it shifts with more authority than it did back when it was electronic. I'd forgotten that I have a "torque lock" system in there for lockup. It still works, and, there again, it locks up with much more feel to it than before we went mechanical.

There were a few issues to be taken care of, some of which have yet to be dealt with. The Gear Vendors exhaust brake was seriousely frozen up and had to come out to be freed up and lubed. I had a lot of white smoke on startup, so, after I installed a Ford tractor relay and push-button in parallel with the glow controller, I changed the glow plugs, and now, I let the stock controller glow for it's 6 seconds, wait for the exhaust brake to cycle, then hit my button and then the starter and it fires on what seems like one turn and I keep up with the glow for another 6-8 seconds and there's very little smoke and it idles smoothly.

The right-rear brake was dragging hard and I had to change the leaky wheel cylinder. RR drag was cured, but now I have the right-front grabbing hard! Can see some wet on the inside of the tire, so I may be into changing the caliper there, and it wouldn't surprise me if I had to work my way around to the last two brakes, too. The good thing about this project is, --- no rust! :D


The AC worked, after we charged it, but started leaking like a sieve. So, I guess we're going to be buying a whole replacement kit for that.

Still, it feels so great to get back into the old Suburban and git on down the road. It still handles sooo well. I guess the Suburban ride is kind of a "solid" feel, or something. I love the Sierra, but there's just something satisfying about being in a Burb seat.:D

[Robyn]

Good to hear Dick

We have had a Burb around here for many years and at times 2 of them.

Just so sad that GM has not gotten their head out of the cat box and offered one with the Dmax in it.

They would sell like hotcakes.

I miss the diesel Burbs

The current work horse is a 95 454 4x4 rig

Got it for near nothing and its a solid truck.

Enjoy

[DickWells]

According to Lance (my son) the 2500 Suburban is no longer made. If true, that's another fail on GM's part, IMHO. Still, Lance's 04 Suburban 1500 is a great car.
Yes, the DM should be in a Burb; it would make a tremendous vehicle. You'd think GM would be selling all the Burbs they could make, given the number of black one's that we see on the government/cops & robbers shows. Maybe the bean counters know what their doing. Ford never made much of a go with the Expedition, either.

Fixed that front brake problem this morning. Turned out, there was no leak in the front, just a streak of grease that fell off the lower ball joint. I pushed the piston all the way in, took the caliper off, and cleaned everything up, then took it out on the road and exercised the brakes, forward and backward, and it stopped grabbing. Guess the long idle time let that caliper piston stick up pretty badly. Will keep close track of it, and replace both calipers if it starts grabbing again. It was so severe that you only had to barely touch the pedal on the dirt driveway and the RF just plane stopped.