Loose shifter bolts on the 4L60-E could be a thing in the no-forward-gears predicament — they escape a lot o' shade-tree mechanics. I's battling this problem in 2021, shifted some sump bolts to pin the cable bracket.

Could be an air leak bypassing the throttle body and idle air control. Check for cracked air pipes.

The THM400 and its replacement the 4L80-E can clog the valve body if neglected. I'd had converter-clutch slip in my now-down-until-further-notice GMC M11006, traced it to normal wear and tear in a stock 4L60-E that should've had an overhaul at 200,000 miles.

I's on the market for a new minivan six years ago, got a GMC M11006 (Safari SLE) passenger wagon rather than a cargo vision van. (The only ones on the used market were cargo panel vans.) Wanted a cargo vision van due to a solid rather than pop-out window on the sidegate (a known weakness with passen...

Gotta be an upfit on a G-Series chassis-cab. (Chevrolet Express, that is.) Don't come stock with cargo vans or passenger wagons.

:poke: Are ye attempting a 4L80-E retrofit, which I've longlisted as a fallback in case the physical brake layout contraindicates a clutch retrofit? The M-body midvan came with the 4L60-E stock from 1996-2001, the 4L65-E from 2002 to end of production. (The Allison 1000 five-speed is too large for t...

:-k Sorry to revive an old Thread, but King's Auto Repair (Oakley, CA, USA) identified the cause for (a) PCM-perceived miss at idle and (b) high NOx indicating lean-out at 15 and 25 MPH per CARB dyno test: Leaky valve(s), #5 cylinder. King's no longer has the resources to fix the leak(s). The Vortec...

MountainManJoe wrote: ↑Mon Oct 10, 2022 7:56 pm

Bret Schmerker wrote: ↑Mon Oct 10, 2022 4:12 pm First time I sent photos to this Website.

It's very easy. Click the attachments tab then hit 'Add files'

Your links are broken by the way (Not that Google allows hot-linking anyway.)

Second attempt:

First time I sent photos to this Website. Not behaving per expectations, but Hyperlinks available:

https://photos.google.com/photo/AF1QipM ... cNOCffwI8t

https://photos.google.com/photo/AF1QipP ... dBKd0B5DE1

On my M11006, I've narrowed the residual miss down to the ignition module (DTC: semi-consistent P0305) after replacing the spark plugs, secondary wires, HVS cap and rotor, even the ignition coil to systematically rule out possible causes - I had the HVS break on the road, traced the root failure to...

For my M11006, I've wishlisted a Cobra® 75 WX ST due to compactness of the remote transceiver and an integrated NOAA weather receiver in the remote unit. Already set up a hanger for the control unit on the starboard of the center console. Wiring is straightforward; the auxiliary "hot at all ti...

:-k I've an M11006 with an otherwise fully-functioning climate control system, notwithstanding a breached refrigerant line (thus the pulled compressor fuse) and a compromised fan-speed switch. Is your climate control system holding refrigerant (not the case for me)? If so, check for a blown compress...

... FAA: 7.5", 2.56 open (1985-1986 Astro) FAF: 7.5", 2.73 open (1988 Astro) FAG: 7.5", 3.08 open (1988-1989 Astro) FAH: 7.5", 3.42 open (1988-1989 Astro) FAJ: 7.5", 2.73 posi (1988 Astro) FAK: 7.5", 3.08 posi (1988-1989 Astro) FAL: 7.5", 3.42 posi (1988-1989 Astr...

Six straight boots at the plug end would be ideal — minimum risk of frying on the exhaust headers. I've taken a Taylor Spiro-Pro V8 wire set under advisement, as 8.0mm OD is the fattest the High-Voltage Switch cap can take.

I pull a 3,800 pound camper with my 2002 AWD Astro that has timbren supports and transmission cooler and standard axles. We get about 10-11 mpg at 57 mph. Could use a little more horsepower when climbing hills but otherwise it pulls ok. Last camping trip was over 1,700 miles round trip. Was not abl...