L3n71b in and out of gear.

[josh_t]

So I've got a 77 b210 with an A/T in it. It was said that the transmission did nothing when it was put in gear. The old fluid was black and had extremely fine metallic flecks in small amounts. It really did nothing with the old fluid, so pumped out a good bit and put about 2.5-3 quarts of new fluid back in it until it was just below the H mark with the fluid warm. It acts like its still low on fluid. It goes in gear and then goes back out. I gave it a little throttle (1300-1500 RPM) to see if it changed any and it didn't. It's in for about a 1/2 second and out a 1/2 second regardless of RPM or gear range. My first thoughts are clogged filter or bad pump. I haven't checked on either of these possibilities yet. Anybody have any input?

[datzenmike]

Black fluid???? :lol: :lol: :lol:

 

 

The black is the worn off clutch material. It shouldn't be wearing off. It's very abrasive and will wear the delicate hydraulic valves and servos. The ATF is there to cool and lubricate the clutches. The biggest enemy of an automatic is HEAT.

 

Towing is the worst thing for an automatic. It generates huge amounts of heat. The oil basically cooks it's self to death and needs to be replaced.

 

I don't expect much from this transmission... but dump ALL the ATF out. While the pan is off change the filter. A plugged filter will inhibit the hydraulic pressure and this is what holds it in gear. Remember that clutch material can't be put back so this transmission is in bad shape.

 

 

Just for fun measure the length of the transmission. 26" or 31.5"???

[josh_t]

I was fully expecting a rebuild anyway when i first seen the fluid. i knew that was clutches and kinda lol'd at the dipstick but i figured i could get it to do something anyway. Its more of a dark brown than a black anyway. and it smelled identical to my last b210's transmission fluid prior to its rebuild. I forgot to add that it only has 63k miles on it. Judging by the condition of the rest of the vehicle including the engine, I'm quite certain that its actually 63k and not rolled over. It's the same stubby trans as my old b210 was so I'm assuming 26". I'll measure to be sure. What would be the difference between the two besides length?

[ggzilla]

Differences between which two???

 

26.3" is the length of all A-series 4-speed manual transmissions. The automatic is shorter then that at about 25.7"

[josh_t]

he said measure to see if its 31 or 26 inches. i'm assuming to see if its 3 or 4 speed or for some other reason. it doesnt have an overdrive housing like the l4n does.

[ggzilla]

3-speed Datsun automatic transmissions come in three different lengths. However all B210 automatics are the same length.

[josh_t]

oh ok. i didnt know that. this car is all original so far other than the alternator, ignition coil and a few gaskets. I would assume its original since it looks the same as my old one did and the driveshaft looks original and unmodified too. i can always check the i.d tag to see if its at least close to the same mfg date as the car.

 

Edit: facepalm. apparently i lied. unless a 728 FU head came stock on an auto car. The tag says 80hp so i'm 99% certain that the head isn't original.

[datzenmike]

26" was just a rough estimate. It would be a shorty. I know some are didn't know if all A series were. This limits you to a replacement from any B-210/210 or early 620 or 510 and swap the bell housing....or rebuild.

 

This trans should not be burnt up like that with so few miles. They will run for the life of the car with only minimal maintenance. How do you drive it? do you try to drift??? and do you tow with it????