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Radiator have to be changed when doing the 5speed swap?


socaldatsun

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I don't see why you need to change the radiator if you are swapping the transmission. I can only think of one reason for changing the radiator in a transmission swap - Automatic transmissions need to run a cooler and it is usually located inside the radiator for most passenger cars. But this does not appear to be the case in your situation.

 

Let us know what you find out, perhaps we are missing a key piece of information...

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First, keep your release bearing collar. That's the thing that hold the release bearing and clips onto the inside end of the clutch arm. The one you have on your 521 right now is mated or matched to the clutch you have. The dogleg should have the same but to be safe keep yours.

Releasebearingcollarwithbearing.jpg

 

Second, keep and use the clutch arm that you have on the 521 even if one comes with the dogleg. Here's why. Your 521 has an adjustable threaded pushrod between the slave cylinder and the clutch arm. In addition, the clutch arm has a hole on the end that the push rod fits through. The dogleg am does not.

521ClutchSlave.jpg

 

Third the rear transmission mount will need to be cut to shorten it and then welded up. Best to bolt the tranny up in place and measure. The mount will look somewhat like this...

F4W63toFS5W71Btransmount.jpg

 

doglegmountfor521001.jpg

 

Fourth, the 521 4 speed output spline has a flange on it and is bolted in to the back of the tranny. The flange in turn is bolted to the rest of the driveshaft. This spline with the flange can be unbolted from the 4 speed and used on the dogleg but the hole where the bolt was will leak transmission oil. The fix, is to hammer a 40mm freeze plug in the end to seal it.

 

4 speed with bolt on spline with flange. You can see the big nut that holds the spline on. When the spline is used on the dogleg that nut won't be there and oil will seep out past the splines.

transF4W63520-521flangeo-p.jpg

 

Dogleg with spline installed. The hole was sealed with a 40mm engine block freeze plug.

521flangeonnonflangeF4W63needsplug.jpg

 

The shifter should come out the stock location or close. The floor has a sheet metal cover plate that can be removed and trimmed or just moved back and drilled and screwed back on. Empty tranny before removing. Fill new on when in with GL-4 or equivalent 80w90 gear oil marked 'yellow metal safe'. Get a dollar store kitchen funnel and several feet of garden hose. (anything smaller takes too long) Run the hose down beside the tranny from the engine compartment and into the fill hole on the side. If cold out warm the oil overnight indoors. It should hold about 2 liters which is close to 2 US quarts. Fill till it runs out and it's full.

 

Tips for 5 speed long life...

 

Never tow, pass, climb steep hills in 5th gear. Fifth gear is for out on the highway cruise speed to lower engine RPMs for economy. Always down shift. Replace the oil every 30K miles. Check oil level every 6 months.

 

 

 

 

 

Oh yeah. Your stock rad is fine. The guy giving that info must have had overheating problems to begin with. I put an L20B in my old 521 and never changed the rad, never had problems with it.

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Can some one tell me if this is true or not, maybe explain what might happen or other things I have to do to make it work right.

 

Well those are the things you need to do to make it work right. :lol: :lol:

 

LOL at the useless info X)

 

Not needed, but not useless info.

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I've heard that the radiator has to be changed for a new one after you put the dogleg trans due to over heating issues?

 

Thats bull shit. If iy dont overheat now why would it later.

 

PS if your truck drives now dont worry about it. just get the 5 speed as a spare when the 4 speed those go.

 

 

Pully a 521 trans is a Pain!!!!!!. Not EZ like a 510.

 

Well I bought the truck with the dogleg in it already BUT doesn't run due to the guy STARTED the disc brake set up and i just picked up his scraps -.- so not exactly sure if something needs to be done. Another datsun owener told me this so not too sure why it has to be done. It was saposed to be up and running this weekend but new job got in the way :( looks like im taking the bus for a while longer

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I've heard that the radiator has to be changed for a new one after you put the dogleg trans due to over heating issues?

 

Can some one tell me if this is true or not, maybe explain what might happen or other things I have to do to make it work right.

 

i swapped out the 3 speed auto for a 5 speed manual in my 85 720 and all i did was cut and crimp the end of the old tranny coolant lines

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