1998 Tahoe transmission issue
David Dunbar
07-20-2012, 10:23 AM
I have a new-to-me 1998 Tahoe for towing my boat. It seems to shift normally for most of the towing I do, but something strange is going on when I pull the boat and trailer out of the water at the boat ramp.
If I shift into normal drive to pull out, the vehicle doesn't move. The only way to get up the ramp is to drop the transmission into low gear. Then it seems to pull out normally. Once on the level I can shift to the normal drive position and the car accelerates and shifts normally.
The oil in the transmission is clean (red). It appears to be overfilled, but I don't know if that is any problem. Anybody else have a problem like this?
If I shift into normal drive to pull out, the vehicle doesn't move. The only way to get up the ramp is to drop the transmission into low gear. Then it seems to pull out normally. Once on the level I can shift to the normal drive position and the car accelerates and shifts normally.
The oil in the transmission is clean (red). It appears to be overfilled, but I don't know if that is any problem. Anybody else have a problem like this?
j cAT
07-20-2012, 02:36 PM
number of issues. the transmission in park ,engine running, at the normal temp and the vehicle being driven about 10 milles the fluid should be not above the full mark. if so get a hand pump used for quart bottles and by attaching a piece of tubing suck out the excess fluid.
if it is so full that you see when hot bubbles then your doing damage.
next what is the boat weight ? what type of trailer and brakes on trailer.
using low gear to pull out of the water is what I use.
when towing you never use OD 4th gear at anytime. you tow in 3rd gear.
this will reduce tranny temps. OD 4th gear towing this is creating high temps.
never check tranny fluid if you are towing. this is because the higher temp will cause the fluid to be slightly over the full mark ..hot fluid expands.
if you have 4000lbs total tow load you need a large tranny cooler external to the ac condensor.
if it is so full that you see when hot bubbles then your doing damage.
next what is the boat weight ? what type of trailer and brakes on trailer.
using low gear to pull out of the water is what I use.
when towing you never use OD 4th gear at anytime. you tow in 3rd gear.
this will reduce tranny temps. OD 4th gear towing this is creating high temps.
never check tranny fluid if you are towing. this is because the higher temp will cause the fluid to be slightly over the full mark ..hot fluid expands.
if you have 4000lbs total tow load you need a large tranny cooler external to the ac condensor.
trannyman52
07-21-2012, 01:51 AM
The difference between drive/low,,,and mannual low is d/l uses the one way roller clutch to apply to make low gear,,,m/l ,,,applys low/reverse clutch to shore-up the roller clutch,,,I would be weary of why the roller clutch is not holding in drive/low........
Overfull ,,by a small amount is not a big issue,,,excessive amounts will cause the oil to foam,,,then slips,,,then junk!!!!....,,,also towing with low fluid level ,,,gets the same outcome,,,,when towing,a quart low is a problem in the making...check often!!!!
Overfull ,,by a small amount is not a big issue,,,excessive amounts will cause the oil to foam,,,then slips,,,then junk!!!!....,,,also towing with low fluid level ,,,gets the same outcome,,,,when towing,a quart low is a problem in the making...check often!!!!
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