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Transmission options - 720 with L20b.


Scomber

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So my transmission is noisy, and it turns out there was quite a bit of metal flake in the lube.  I'm not sure this transmission is going to live.  This is (as I said) a 720 with an L20b, which means it's a 1980 model year.

What years of trucks and motors will have compatible transmissions? I understand the Z24 leans over, but the tranny mates up? 

What are my options?

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I assume that you changed the oil?

 

The '80 720 (I assume 2wd) has wide ratio gear set same as the '79 620. This is the only exact transmission other than another '80 720.

 

 

If not concerned with carrying heavy loads a mid ratio transmission can easily be substituted. The following L series 5 speeds are all mid ratio...

 

'77 and '78 620 

'77-'78 280z

'79 280zx  (only this one year)

'77-'80 810 and '81-'81 Maxima

 

The only other L series 5 speeds are the close ratio only used on the '80-'83 non turbo 280zx. It will fit and work fine on an empty truck, but if used for work or hauling a heavy load you will find that first is harder to take off in. It's intended for lighter cars or cars with larger displacement engines and not a heavy truck with small L20B and 3.90 differential.

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Thanks. 

Let me explore another avenue.  If everything inside is too crunchy, how hard is it (with a clean space and normal hand tools) to take this thing apart and replace the shaft bearings?  That seems like it would be relatively cheap, parts wise, but would... uh... stretch my skill set.  Then I'd just live with whatever gear slop there was, knowing the thing isn't just going to go BANG on me.  How big of bearing press would I need?

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