New-to-me 720 Lot's of Questions!

1980-1986 Datsun 720 forums. All 720-specific topics and discussion can be found here.
Demihuman
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Car: 83 720

New-to-me 720 Lot's of Questions!

Postby Demihuman » Mon Dec 29, 2008 1:50 pm

Hi everyone, I just got a 720 and while it old and fifth gear doesn't work I realy like it so far!

I found a used tranny with waranty from a shop for $350 does that sound reasonable?

It is very hard to get into fifth and it pops put of fifth with any deceleration. I also hear a little grinding when I put it in reverse but it sounds like it may be comming out of the rear-end does anyone know what that is?

I am probably going to replace the clutch when I do the transmission. Looks like there is an exedy stage 1 for around $150 or just an OEM for a $100 any thoughts?

I also need new seats REALLY bad! Does anyone know what fits in the 720?

OK, fun questions: How much HP can I expect from a cat back exhuast? how about a weber carb? any other real obvious performance mods?

It seems like the Nissan/Datsun old truck forums are in flux so if anyone can point me toward the info I would appreciate that too!

Thanks


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phlebmaster
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Car: 1973 240z L26 4spd rip roar and ready to go!

Re: New-to-me 720 Lot's of Questions! (Demihuman)

Postby phlebmaster » Mon Dec 29, 2008 2:01 pm

WELCOME TO THE FORUM!

My advice is to look into junk yard prices before you pay $350.00 for a used tranny. The warranty is only as good as the paper it is on, and they are just taking a chance that the used tranny doesn't break before the warranty is up. Your odds may be better going with the JY route if you have a way to install it yourself.

Go with a new clutch...stockers are just fine unless you plan on drag racing or pulling.

Anyway, we like pics here so post some up of your ride.

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IMH
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Re: New-to-me 720 Lot's of Questions! (Demihuman)

Postby IMH » Mon Dec 29, 2008 4:03 pm

You could replace the baulk rings, seals, etc. in the trans you have. In other words, do a minor rebuild. It would cost less than the trans from the shop and you'd know what you have when compared to a junkyard tranny. When I buy a trans from the junkyard, I always do a minor rebuild on it before I install it. I really don't like the possibility of doing a job twice.

Demihuman
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Car: 83 720

Re: New-to-me 720 Lot's of Questions! (IMH)

Postby Demihuman » Tue Dec 30, 2008 8:41 am

Hey IMH, Do you think if fifth gear is really chewed up a rebuild will help? I mean wouldn't I need to replace the actual gears? How hard is it to do?

I have never cracked open a transmission but I am not totally adverse to the idea. It sounds like a refresh of the new tranny is a good idea anyways.

So it looks like there are some 50% sales at pick and pull this week. So that could be like $50-100 for a tranny. I will see what I can find.

Also I will get some pictures up soon!

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breadbox
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Re: New-to-me 720 Lot's of Questions! (Demihuman)

Postby breadbox » Tue Dec 30, 2008 12:41 pm

You could get a new exedy oem replacment clutch. Mine for the 240 was like $103.

Don't forget to put some money down first to do a tune-up and replace all fluids.

Demihuman
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Car: 83 720

Re: New-to-me 720 Lot's of Questions! (Demihuman)

Postby Demihuman » Sat Jan 17, 2009 2:35 pm

So I got a new tranny of the correct length at pick n' pull for $120. it was in an 83 4x4 king cab just like mine with 160k on the odo. I also scored a factory service manual for like $8 on amazon. Did a bunch of research on transmission anatomy and how they are supposed to work. I pulled the tranny apart today and it looks pretty good.

The baulk ring on 2nd is pretty worn, about .05 mm smaller then the shop manual says is good. the end play on the gears is about .005 to big on all but third and reverse looks pretty chewed up.

You can see the reverse counter-counter gear hear. I think the right side of the teeth should look like nice sharp wedges but instead they look more like bullets [IMG]<table style="width:auto;"><tr><td></td></tr><tr><td style="font-family:arial,sans-serif; font-size:11px; text-align:right">From 83 720 trans</td></tr></table>[/IMG]

Here is the notorious fifth gear. To me it doesn't look too bad what do you guys think? [IMG]<table style="width:auto;"><tr><td></td></tr><tr><td style="font-family:arial,sans-serif; font-size:11px; text-align:right">From 83 720 trans</td></tr></table>/IMG]

Here is the ride:

[IMG]<table style="width:auto;"><tr><td></td></tr><tr><td style="font-family:arial,sans-serif; font-size:11px; text-align:right">From 83 720 trans</td></tr></table>[/IMG]

four wheeling over some gnarly cardboard ;-)

[IMG]<table style="width:auto;"><tr><td></td></tr><tr><td style="font-family:arial,sans-serif; font-size:11px; text-align:right">From 83 720 trans</td></tr></table>[/IMG]

I think after we get the trans all worked out and the engine in a nice tune I am going to get some nice black steel "crawler" style rims and some knobby tires!

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breadbox
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Re: New-to-me 720 Lot's of Questions! (Demihuman)

Postby breadbox » Sat Jan 17, 2009 4:27 pm

First thing I did after I got my 720 was replace the fluids.

Demihuman
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Car: 83 720

Re: New-to-me 720 Lot's of Questions! (breadbox)

Postby Demihuman » Sun Jan 18, 2009 11:57 am

Yes fluids are very important. Right now I am working on the transmission. When I put it in the truck I will definitely use new fluid. I have a big box of redline all ready just for that. I will also change the fluid in the diffs and the transfer case. The oil and coolant are fresh already.

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breadbox
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Re: New-to-me 720 Lot's of Questions! (Demihuman)

Postby breadbox » Tue Jan 20, 2009 5:31 am

And get an oil pump to fill your trans. I didn't use one and ended up filling it with some fish tank hose with a funnel in it thru the shifter hole. It took like an hour and a half for it to fill by gravity and it spilled a bit on my passenger monster mat and the truck smelled like trans fluid for a while.

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PEZi
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Re: New-to-me 720 Lot's of Questions! (breadbox)

Postby PEZi » Tue Jan 20, 2009 1:41 pm

yeah the trans is annoying

i used a cut up garden hose... one end in the trans the other up through the engine bay.... it worked ok

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IMH
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Re: New-to-me 720 Lot's of Questions! (PEZi303)

Postby IMH » Wed Jan 21, 2009 1:45 am

That's gear lube not 'trans fluid'. Use a pump. It's a lot faster and not nearly as messy. Fill it through the hole in the side of the trans. That's whait it's for. If you fill it through the shifter hole, you'll over fill it.

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PEZi
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Re: New-to-me 720 Lot's of Questions! (IMH)

Postby PEZi » Wed Jan 21, 2009 9:15 am

not sure if i made it apparent or not that i did you the hole on the side of the trans.... i didn't even realize bread was talking about filling it from the top.... i didn't realize that was even possible

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IMH
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Re: New-to-me 720 Lot's of Questions! (PEZi303)

Postby IMH » Wed Jan 21, 2009 9:25 am

PEZi303 wrote:not sure if i made it apparent or not that i did you the hole on the side of the trans.... i didn't even realize bread was talking about filling it from the top.... i didn't realize that was even possible
I was more or less responding to both. I have a fluid pump but even a hand pump like the ones they sell for the 1 gallon and larger containers of gear lube make the job much easier than a 'gravity' fill.

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PEZi
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Re: New-to-me 720 Lot's of Questions! (IMH)

Postby PEZi » Wed Jan 21, 2009 11:35 am

yeah i can imagine... i need to get one for next time

zedman280
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Re: New-to-me 720 Lot's of Questions! (Demihuman)

Postby zedman280 » Sun Jan 25, 2009 6:10 pm

As for your SEATS question.

Pretty easy to fit just about anything in there. However, I threw a pair of high back buckets out of my old 83 280zx. Took the sliders off the stock seats and threw them onto the 280zx buckets, and I believe I only had to drill holes in teh rear of the seat to mount the sliders up and everything else bolted up perfectly. Too easy, they are way more comfortable and look better !!


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