ACK! My beater needs a transmission!!!

[Jarlaxle]

Originally Posted by CHEESE_WAGON

And many a TH350/TH400 has topped 200k without fuss or muss.

So have many TH700's and 4L60E's. It wasn't mileage that killed it, it was towing THREE TIMES WHAT THE CAR WAS RATED FOR with no trans cooler. 400-degree ATF will cook a TH350 just as easily as a 4L60E. The TH-200-4R in my 1989 Olds wagon was untouched with 225K. I have close to 65K on the TH-200-4R in my Coupe de Ville, in a 4600lb car capable of a low-12-second 1/4 mile run.

The 4L60E in my 2000 Safari already has harsh upshifts and downshifts at only 128k, and they are known for this. My dad's '97 S-10 is the same way,and has been for awhile. Another reason to tell the government to put a sock in it. In order to satisfy EPA requirements, automakers have to build weak, overcomplicated junk.

How badly do you beat on it? I've seen them wind up 150-200K in livery vans.

Heh. Let's see someone tow consistently with any of these, even within specified payload limits

How about a GCW of close to 28,000lbs behind a BB Chevy? That was a TH-700, going strong with about 55K, in a tag-axle Pace Arrow motorhome used to pull a Super Bee on a trailer. The Super Bee alswo had a TH-700, behind a fire-breathing crossrammed EFI 426 Hemi. (Yes, I absolutely did say it has a crossrammed EFI 426 Hemi!)

[the_experience03]

You can swap to a TH350 if you really want to. The PCM will need to be reflashed or a unit from a manual transmission van installed (yeah right...don't think they existed). VSS simulators that plug into the old cable drive speedo ports are readily available.

[Jarlaxle]

Big-block engine. TH-700-R4 transmission. Tag-axle class A motorhome. Dodge Super Bee on a trailer. Combined weight 28,000lbs, which is MORE than your bus! 55,000 miles without a problem. Try that with a TH-350.

500+HP crossrammed EFI 426 Hemi (winding to 8000RPM). 3500-stall (lockup) TH-700-R4. 11-flat, 3900lb car. Multiple 2000+ mile road trips. Multiple 1/4 mile blasts. No more need be said. I've also seen one wind up 70,000+ miles behind a 502 in a 4000+lb GMC Sprint SP.

Your transmission rebuilder is clearly either crooked or really stupid. Did you use AAMCO, by any chance?

Again: I worked for a livery company. NOT ONE SINGLE TH-700-R4 or 4L60E failed before 100,000 miles. Most went over 150K. Your van probably has a bad TPS. You need to fix this before it cooks the transmission. But whatever...you'll probably just keep driving it the way it is until it fails, and then yopu'll blame the transmission for YOUR neglect.

[Jarlaxle]

If it's partially failed, it may be giving a reading...just the WRONG one. A total failure would trip the CEL (and might make the engine refuse to idle), but I have seen them give reasonable (within parameters) but inaccurate readings. I have seen them do EXACTLY what your van is doing (and wow, was THAT a head-scratcher), on a vehicle with the identical drivetrain. Is it a TBI or a Vortec V6?

Again: If this is the problem it WILL cook the transmission!

Alternately...the ABS light makes me think it might be a VSS problem. If it isn't getting a correct reading from the driveshaft (rear ABS sensor is, IIRC, in the trans tailshaft), it might trip the light. Here's a test you can do yourself in 2 minutes: find a big parking lot, dirt or (better) snow-covered. Take the van to maybe 20-25MPH & nail the brakes. Jump out & see if the rears locked. Do the speedometer & odometer work properly?

Also, if I remember Astros properly, there should be a ground strap from the fuel tank to the chassis...if missing, it can make the fuel gauge freak out.

[Jarlaxle]

V8's were TBI until 1995, later on some vehicles (someone on here has a 1998 with a TBI 350)...the CPI you're referring to IS the Vortec, if it's what I'm thinking. It's a batch-fire multipoint setup.

[the_experience03]

Originally Posted by Jarlaxle

V8's were TBI until 1995, later on some vehicles (someone on here has a 1998 with a TBI 350)...the CPI you're referring to IS the Vortec, if it's what I'm thinking. It's a batch-fire multipoint setup.

Single injector batch fire port fuel injection... Later ones got CPI that looked more like the big trucks with individual injectors and sequential injection, but they still used the spider and poppet valves under the upper plenum.

[Jarlaxle]

I recall the later ones (until the LS-based engines in 1999) were still batch-fire, not sequential.

[Jarlaxle]

Err...not exactly. F-cars were TBI (305) or TPI (305 or 350) until 1992...1993's got the LT1. Corvettes got the LT1 in 1992, B-bodies got it or the 4.3 litre "baby LT1" V8 in 1994.

V8 trucks (305, 350, 454) were TBI across the board--even the 454SS--until 1995. The pickups, Suburbans, & vans got the Vortec engines--also across the board--for 1996 to comply with OBD-2. (The TBI was basically mid-80's technology & not compatible with OBD-2.) The big commercial chassis (motorhomes, MDT's, Stepvans) had more lenient requirements, and were TBI until about 1999. (Heck, they had carb'd 454's, TH-475's, & no catalysts until 1990!)

Vans got Vortec engines the same time as pickups, but they ran longer. The redesigned 1999 Silverado got the LS-based engines (4.8, 5.3, 6.0--also called Vortecs), but the vans ran the old 305 (Vortec 5000) & 350 (Vortec 5700) until at least 2000, maybe 2001.

The early Vortecs were NOT sequential, they were batch-fire MPI. (Neither were the TPI Camaro/Corvette engines, including the L98, they were bank-fire.) As I recall, the 305, 350, and 454 never got sequential injection...not sure when the V6 did, but probably around 1999 or 2000.

[the_experience03]

Originally Posted by Jarlaxle

As I recall, the 305, 350, and 454 never got sequential injection...not sure when the V6 did, but probably around 1999 or 2000.

The 96+ Vortec small blocks were SEFI. I'm not positive on the 454.