I have two 700's one 2wd and the other 4wd.  Both units do not will not move in reverse.  trans fluid are cherry red not burnt and move through all the gears in drive.  what could the problems be?  

The common element is the reverse input clutch in front of tranny. Clutch could be bad or valve body issues routing oil to it. Also when reverse is selected fluid for clutch is routed through a boost valve to boost line pressure applied to this clutch. There could be a problem there. Strange that you have same problem on two trucks unless maybe you have crowded both a lot in reverse in past. In reverse power is cleverly routed through outer drums and around forward gear clutches and then coupled back to output main shaft via lo/rev clutch in rear of tranny. Since forward gears work we can assume no problems there.  

I forgot to mention that the fluid in both trucks is about 4" above the full mark on the dip stick and I did not over fill the trans and on the 4x4 I was pushing snow and high sided the truck rocked it in and out of reverse and then it was gone.  I do not know why the fluid is high and on both trucks?  I am planning a trans flush, but in the area I am in I have to travel 70 miles to have it done.  

You did not mention being stuck and it failing. THis points to mechanical failure. On the high fluid it would "tend" to suggest that there is a failure in the reverse clutch circuit and it is not holding oil in it. This would cause fluid to read high but also if you have a leak in tranny cooler in radiator that is letting coolant into tranny, that could cause it to read high too.

BTW, you are checking fluid level with engine running correct?  

ok but that does not explain why the 2wd is doing the same thing.  I have been checking the fluid with the engine running and the trans and antifreeze are the correct colors.  the reverse just stopped working in that one too, and when I step on it, it does not like to drop into a lower gear.  What would the fix for the reverse cluch ciruit be?  

if reverse and low is out the clutches are burnt, they can get toasted without majorly discoloring the fluid over time.
if it's not kicking down the tv cable is out of adjustment which causes premature failure.

I just built a 700r4 last week that was only missing reverse. its not uncommon, the reverse clutch pack in the bottom of the case was burnt and also ruined the steals. they had also been towing with it in OD, the direct pack had a black ring around em.

if the cooler had a leak it would empty the tranny fluid into the radiator as soon as it was started. a small pin hole spews alot of fluid in a hurry.

sticky valves are the result of a wasted convertors and clutch material.

burnt performance 8 stack...

 

discoknut:
ok but that does not explain why the 2wd is doing the same thing.  I have been checking the fluid with the engine running and the trans and antifreeze are the correct colors.  the reverse just stopped working in that one too, and when I step on it, it does not like to drop into a lower gear.  What would the fix for the reverse cluch ciruit be?

The lack of down shift suggests that TV cable is not set right or there is a issue with it in valve body. While many off the clutches in tranny share functions in that they are used for more than one range or gear selection while the reverse clutch in front of case is only used in reverse. The oil feed circuit for it is pretty simple in that fluid from manual valve is routed to a orifice and check bal. The ball seats to force oil through orifice to slow/cushion engagement at idle. You could think that orifice is plugged but then there is a device called a "abuse valve" (strange name) that bypasses orifice and check ball at higher engine RPM so reverse would work if you raised RPM in it is pump was working normally which points to clutch. (pressure and flow) One other possibility is the manual valve attached to gear shifter. It has two separate ported circuits off it. On each to feed low/reverse clutch circuit and the other to feed front reverse clutch circuit. It is possible for this valve to be out of adjustment via linkage. If this was the case try move selector slight past "R" position in both directions (one at a time) to see if reverse engages. If it does then linkage is out of adjustment.  

the valve has no adjustment, the detent locks it securely into place with a flat spring and roller tip.

it would prevent all the gear selections from holding if it was broken or loose.

 

Generally this is true but if detent is worn it could cause misalignment. Point is if moving shifter a little causes it to work then it points to range selector valve.  

Thanks Guys I will try what you suggested and hope it all works out just fine.  I sure get better and quicker answers in here then any shop I speak to.  Thanks again  

it's highly unlikely to find a tranny with a worn out detent or roller, that why they use em.  

mudb8_:
it's highly unlikely to find a tranny with a worn out detent or roller, that why they use em.

All is not as it seems. My 89 since it was new would not always click into OD properly when you shifted it there and some times on rare occasions OD would not work until to wiggle shifter a bit. Never got any worse in 19 years but it still does it on occasion. It seems that some of a dentents are not as positive an exact as they should be.