R180 vs. R200 differential in a 1973 240

[coolwildflower]

my boyfriend wants to help me with the rear end, on my 73 240 z. he thinks it may be a R200 in there, how can we be sure that we need a new rear end, and how can we be sure if it is a R180 vs R 200, etc. any help on rebuilding rear end please. i tols hi, that i was driving on freeway about 75 mph and suddenly i lost power and could not get the car to go any faster than 35-40 mph, it just all of a sudden had no power . i drove it all the way home in 3rd gear. he said it sounds like the rear end. took offthe rear brakes and found them both worn down. any advice?

[olzed]

When you stopped were the brakes smelling hot.

What makes you think it is your differential that is causing concern. Is there grinding noises from the rear of the car.A bad diff. will make noises.

More info is good. A collapsed hub bearing can also make some awful noises.

[Carl Beck]

... i tols hi

Is that supposed to be "I told him" ?

... that i was driving on freeway about 75 mph and suddenly i lost power and could not get the car to go any faster than 35-40 mph, it just all of a sudden had no power . i drove it all the way home in 3rd gear.

With a 73 it could be simply a matter of a partial vapor lock in the fuel lines - had you recently filled the gas tank? It could be simply a matter of a plugged fuel filter. It could be a fuel pump going bad.

..... he said it sounds like the rear end. took offthe rear brakes and found them both worn down. any advice?

Yes - get a boy friend that knows something about cars. Keep the boyfriend you presently have away from your Z.

Differentials that are badly worn - make a lot of noise {as previously mentioned}

Differentials that break - stop your car from moving all together.

If the rear brakes were dragging - it would wear out the rear brake shoes, but it would also result in a lot of heat and most likely a lot of smoke...

First try changing the in-line fuel filter - it is on the inner-fender, on the passenger side of the car. Take it out - take it to the Parts Store near you - and match it up with a new replacement.

Find a good Z mechanic near you...

FWIW,

Carl B.

[Darrel]

The '73 should also have an electric pump back by the tank. It has a filter inside.

[tlorber]

I think the boy friend just wants to mess with your rear endROFL

Come on! Someone had to say it.

[IdahoKidd]

How does on tell someone their girlfriends rear end is worn out?

[olzed]

I didn't like to say as much, but seeing as how Carl has, it sounds as though boy friend is guessing .

Can you be more specific with your description of your problems.

Does the car make horrible noises? If not, your differential, or, as you put it, your rear end, is probably fine.