CANADA4RNR

Looking for a diagnosis for my 4 low Gear, 4 high works fine but switch to low from park or neutral and there is a bad grinding noise and the truck hardly moves and almost jumps ... I'm not familiar with how the gears work... any thoughts opinions why this would be and why only 4 low... 4 hi works fine and thats all i ever use but I would like to get 4low fixed ?? diff fluid good aswell. thxs

celica

Are you in nuetral or park when trying to put it in 4 low. 4 low is not shift on the fly, only 4 high

regularguy412

Check your A/T fluid. Chances are good that you have an A340H Auto tranny with integral transfer case. Not sure that too low or too high fluid would cause a problem, but the t-case shares fluid with the tranny on the A340H. I do know that having too much fluid in the tranny will cause it to overheat. Don't ask me how I know.

Mike in AR

Marc

The fluid levels in the A340H transmission and the transfer case are independant of each other.

They are not shared. If you are going to check them, you should check both.

Also, with the A340H you can shift into 4 low at speeds less than approximately 18 mph (30 kph)

(the above info applies to a 91 3.0 Auto)

regularguy412

Might want to check this info:

http://www.4x4wire.com/toyota/tech/autocrawler/

See the info under :A340H to A340F transmission swap,, 1st paragraph.

Also here:
http://personal.utulsa.edu/~nathan-b...32prelimin.pdf

The levels can be checked independently, but when refilling both the tranny and transfer case after draining both via drain plugs, the FSM instructs all fluid to be refilled via the filler tube and not thru the sight plug holes. This indicates that the fluid in the tranny is integral and shared by the transfer case. Otherwise, the transfercase would not get refilled by using only the filler tube on the transmission.

Mike in AR

Jeffires

I have the same setup (Auto w/ manual hubs) and have never had any trouble with mine. I do know that the transmission and transfer case fluids must be checked separately. I know they say you can shift in and out of L4 while moving, but I have always stopped and gone to transmission N first.

Marc

I believe that info is misleading, otherwise when I drain my transfer case why does only 1.2 litres of fluid come out?

I do think they are integrated but do not share fluid.

regularguy412

Hi Marc,, I added another link to the FSM on my last post. If you'll scroll down, you'll see the procedure. There is a cutaway view of the tranny/ transfer case in that same FSM ( but not the specific link I posted ). Here is a link to the cutaway. You can see that it's really one BIG case and the shaft goes all the way through.

http://personal.utulsa.edu/~nathan-b...27descript.pdf

Three months ago, I drained all the fluid from my tranny and transfer case and replaced it. I added the total amount of fluid needed for a drain and refill of both. When I replaced the fluid, I put the entire amount for both tranny and t-case in thru the filler tube, per the FSM. I ran the gears and checked the fluid level on the tranny dipstick. It was not overfilled. The transfer case is hydraulicly actuated, just like the tranny. I doubt it would go into 4H or 4L without hydraulic pressure and I've run it in 4H and 4L for short durations since then.

Mike in AR

CANADA4RNR

Works now....weird...maybe wasn't engaging it properly who know...