Long 5 Speed swap from short 4 speed

[Neatus]

I have acquired a long tail 5 speed from a late model 620 to put in my 73 620 which has the short 4 speed.  I have also got the crossmember and the front shaft from the 5 speed truck.  Besides a new clutch kit are their any other items I should get before embarking on the swap?  Searched the 5 speed swap threads and read a lot but just want to make sure my truck isn't down for days once I pull the trans.  Thanks for any help!

[datzenmike]

That should work. I would replace the rear seal where the driveshaft spline enters the tail. They are only $5 but a lot less trouble to do while the transmission is out.

 

Keep and use the release bearing collar that is matched to your current pressure plate. If the 5 speed comes with one don't use it. I would definitely replace your old release bearing. Again it's a cheap part but impossible to get out later without removing the transmission again.

 

You can use your 4 speed clutch slave on the 5 speed.

 

You can use the 4 or the 5 speed clutch arm. Grease the clutch arm pivot ball with lithium grease.

 

For oil use GL-4 (NOT GL-5) 80 or 90w is fine. You'll need 2 liters to fill the 5 speed.

 

 

You may need to change the speedometer pinion gear to correct the speedometer reading. This can be done from the outside easily enough. See if your speedometer is out first.

 

Your 4 speed speedometer cable will reach the 5 speed position even though it's 5.5 " longer and on the other side. Disconnect and un-clip the speedometer cable and pull up into the engine compartment. Push it down behind the head, diagonally over the top of the transmission to the right rear. I've done the same F4W63L 4 speed to a 71B 5 speed in a car and it fits.  There's just enough cable.

 

 

[Neatus]

12 minutes ago, datzenmike said:

That should work. I would replace the rear seal where the driveshaft spline enters the tail. They are only $5 but a lot less trouble to do while the transmission is out.

 

Keep and use the release bearing collar that is matched to your current pressure plate. If the 5 speed comes with one don't use it. I would definitely replace your old release bearing. Again it's a cheap part but impossible to get out later without removing the transmission again.

 

You can use your 4 speed clutch slave on the 5 speed.

 

You can use the 4 or the 5 speed clutch arm. Grease the clutch arm pivot ball with lithium grease.

 

For oil use GL-4 (NOT GL-5) 80 or 90w is fine. You'll need 2 liters to fill the 5 speed.

 

 

You may need to change the speedometer pinion gear to correct the speedometer reading. This can be done from the outside easily enough. See if your speedometer is out first.

 

Great info.  Release bearing ordered and will pick up some oil here today or tomorrow. Will reused my slave as it is almost new.

 

My speedo currently reads 5 MPH fast.  I will install the tranny then once I know how far it is off I will pursue fixing it.  

 

Thanks for the information amigo!

[Neatus]

1 hour ago, datzenmike said:

That should work. I would replace the rear seal where the driveshaft spline enters the tail. They are only $5 but a lot less trouble to do while the transmission is out.

Is that called the output shaft seal or the input shaft seal?  Should I just replace both?

[datzenmike]

Output.

 

Sure you can change in input seal also. Never hurts. Remove the 5 bolts but don't hammer on the snout to loosen. Instead, slide a socket extension through the clutch arm hole and hammer against the clutch arm pivot ball. (ask me how I learned this the hard way)

 

In both cases grease the seal lips so it doesn't start turning dry.

 

[Neatus]

Copy all.  Thanks!