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620 Transmission Identification


Digger48

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The second 4-speed transmission I have put in my '73 620 has failed (froze in 4th gear, after increasing tendency to "grind" when shifting unless eased into gear--synchro unit?).  So I am looking for a replacement transmission.  I have read as many threads as I could find on this forum and would very much like to find a FS5W71B (5-speed).  I have located a couple transmissions in a yard in the mid-Willamette Valley with chalk numbers on them.  I have tried to find a web site that might help identify those transmissions (assuming they are Hollander #s)  The numbers are:

51873B  and

8-1174 (the yard owner thought that old Hollander books used an "8" prefix, but he couldn't find one in his office)

 

Does anyone know how I can identify the transmissions with the above numbers on them?  Alternatively, anyone know where (in any state in the NW, including BC) where I might find a FS5W71B ??  Thanks for any suggestions

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Also possible the clutch disc is dragging. It may be damaged or the pressure plate from a broken diaphragm finger.

 

Seizing up could simply be from lack of maintenance (ran out of oil or wasn't changed on time)

 

These real possibilities need to be eliminated before spending more money on another.

 

 

The 71B does not 'drop in' although it will bolt right up to your L16. It about 5.5" longer so it needs the trans mount modified and the drive shaft shortened. You might try a shorter front drive shaft (they are two piece) from a '74 and up which DID use the 71B transmission. Get the mount and cross member with it. Be sure to keep and use the release bearing collar (but replace the bearing) that you have now do not use what might be on a replacement transmission. If no clutch arm you can use the one you have now. You can use your clutch slave but make sure it's working properly first.

 

The only way to know you are getting a 5 speed 71B for an L series engine is to know what you want and know one when you see it. Wrecking yards can't be trusted for this, they mean well but sometimes they are only saying what they wer told about them.

 

First there were 71B 5 speeds used with L, Z, CA and LD series engines. You need to verify that it even IS for your L series.

 

AaDPhXR.jpg 

 

This is an L series front case where it bolts to the engine. See that rib that runs up the center line? The bolt holes on either side bolt into the block either side of the head. The rib is closer to the left one. Just remember that hole on LEFT is L series.

 

FkMQpJs.jpg

 

It's common for yards to mistake a Z series 71B for an L series. Here's a Z series. Bolt closer on the right =  no good.

 

 

Next is it a 4 or a 5 speed? Don't buy a 4 speed if what you want is a 5 speed. Know the difference at a glance.

4 SPEEDS...

 

Always have this 6 bolt rectangular cover plate with breather on it just forward of the shifter.

BvMKlFr.jpg

 

5 SPEEDS...

Do not.

oEyImGv.jpg

 

 

There were three internal gear ratio options on the 71B. They will all work just fine in a truck. You may be just lucky enough to even find a 5 speed so does it really matter that much?

You can't always expect the correct transmission in a vehicle after 40 years. Lots of things get swapped to keep them on the road. Transmissions can be identified, or more likely identified as to what they are NOT by some of the switches, positions of the speedometer pinion, if it has a reverse check sleeve and the mount that may have been left on it. Usually a combination of things.

 

So if you have some pictures of these transmissions I can take a look for you.  Try to shoot the positions like the one I have posted.

 

Here's a dime quarterly article (Vol 11 Issue 4) on identification of Nissan transmissions... mostly for 510 swaps but still pretty good. This guy really knows his transmissions...

 

KUF49dv.png

 

kjDCB5h.png

kf7qJem.png

 

jKZ4YBz.png

 

d3xrhHw.png

nibw0jK.png

 

KYVbyBH.png

 

BmQvQI4.png

.

ibNXJFW.png

 

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On 7/31/2018 at 1:16 PM, datzenmike said:

Two transmissions? Better check your slave is moving properly or needs bleeding or you'll go through another in short order. Did it grind going into reverse???

 

 

Mike,

The first transmission was the original ('73).  It started making a rattling noise in 3rd & 4th gear.  When I dropped it and opened it up I found that one of the main shaft bearings had a broken bearing cage (that keeps the ball bearings equally spaced).  I found I could get a new bearing for about $150 but when I started looking at what it would take to replace it, I decided it required skill, tools and savvy beyond my pay grade.  So I happened on to a guy who was rebuilding a '73 620 who wanted to replace his 4-speed with a 5 speed and sold me his for $100.  I cleaned it, looked inside for any broken gears and, not seeing any, put this 2nd tranny in my truck.  I put new fluid in, a new clutch and pressure plate and started driving it.  The clutch seemed to work fine.  At first I noticed that this 2nd transmission was a bit touchy going into 2nd, so I just shifted slowly and eased it in without grinding.  After maybe only a hundred miles of driving , it started getting touchy going into 3rd and 4th.  Then  as I was driving home it would not come out of 4th gear.  The clutch worked OK  (I sat in the cab and depressed the clutch so it would roll onto the flat bed to get home).  In neither transmission did it grind going into reverse.

 

I assume that just a visual is how you would check slave movement. How can you tell if the slave needs bleeding?   

Thanks.

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  • 2 weeks later...

Mike,

Here are three pics of a transmission that a yard in Oregon says came from a Datsun.   I am hoping to find a 71B for my L16 engine.  None of the transmissions pictured in that tech bulletin you sent are exactly like this.  Any idea what this might be?   (The other transmission I mentioned was definitely a 4-speed as it had the 6-bolt cover plate).  The (8) 1174 number may be a Hollander reference number (according to the yard owner) but I can't find a Hollander table or site to check that.  Thanks.  c4xpIRW5rjG7aoRWhJRNSuo14Ii5iKfkpTV4MJDnNQNWaACKX-iX7DKK5FloFEMTNbr7OmIrzQftDHSmkCHNa_mJK36RhEdqTVF3s4_VVSy0pkZIVsGQEFAk

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11 hours ago, Digger48 said:

Mike,

Here are three pics of a transmission that a yard in Oregon says came from a Datsun.   I am hoping to find a 71B for my L16 engine.  None of the transmissions pictured in that tech bulletin you sent are exactly like this.  Any idea what this might be?   (The other transmission I mentioned was definitely a 4-speed as it had the 6-bolt cover plate).  The (8) 1174 number may be a Hollander reference number (according to the yard owner) but I can't find a Hollander table or site to check that.  Thanks.  c4xpIRW5rjG7aoRWhJRNSuo14Ii5iKfkpTV4MJDnNQNWaACKX-iX7DKK5FloFEMTNbr7OmIrzQftDHSmkCHNa_mJK36RhEdqTVF3s4_VVSy0pkZIVsGQEFAk

 

Not seeing a picture.

 

The Datsun name was used on some Nissans through '86 even. Last L series 5 speed was '84.

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  • 4 years later...
On 7/31/2018 at 5:15 PM, datzenmike said:

Also possible the clutch disc is dragging. It may be damaged or the pressure plate from a broken diaphragm finger.

 

Seizing up could simply be from lack of maintenance (ran out of oil or wasn't changed on time)

 

These real possibilities need to be eliminated before spending more money on another.

 

 

The 71B does not 'drop in' although it will bolt right up to your L16. It about 5.5" longer so it needs the trans mount modified and the drive shaft shortened. You might try a shorter front drive shaft (they are two piece) from a '74 and up which DID use the 71B transmission. Get the mount and cross member with it. Be sure to keep and use the release bearing collar (but replace the bearing) that you have now do not use what might be on a replacement transmission. If no clutch arm you can use the one you have now. You can use your clutch slave but make sure it's working properly first.

 

The only way to know you are getting a 5 speed 71B for an L series engine is to know what you want and know one when you see it. Wrecking yards can't be trusted for this, they mean well but sometimes they are only saying what they wer told about them.

 

First there were 71B 5 speeds used with L, Z, CA and LD series engines. You need to verify that it even IS for your L series.

 

AaDPhXR.jpg 

 

This is an L series front case where it bolts to the engine. See that rib that runs up the center line? The bolt holes on either side bolt into the block either side of the head. The rib is closer to the left one. Just remember that hole on LEFT is L series.

 

FkMQpJs.jpg

 

It's common for yards to mistake a Z series 71B for an L series. Here's a Z series. Bolt closer on the right =  no good.

 

 

Next is it a 4 or a 5 speed? Don't buy a 4 speed if what you want is a 5 speed. Know the difference at a glance.

4 SPEEDS...

 

Always have this 6 bolt rectangular cover plate with breather on it just forward of the shifter.

BvMKlFr.jpg

 

5 SPEEDS...

Do not.

oEyImGv.jpg

 

 

There were three internal gear ratio options on the 71B. They will all work just fine in a truck. You may be just lucky enough to even find a 5 speed so does it really matter that much?

You can't always expect the correct transmission in a vehicle after 40 years. Lots of things get swapped to keep them on the road. Transmissions can be identified, or more likely identified as to what they are NOT by some of the switches, positions of the speedometer pinion, if it has a reverse check sleeve and the mount that may have been left on it. Usually a combination of things.

 

So if you have some pictures of these transmissions I can take a look for you.  Try to shoot the positions like the one I have posted.

 

Here's a dime quarterly article (Vol 11 Issue 4) on identification of Nissan transmissions... mostly for 510 swaps but still pretty good. This guy really knows his transmissions...

 

KUF49dv.png

 

kjDCB5h.png

kf7qJem.png

 

jKZ4YBz.png

 

d3xrhHw.png

nibw0jK.png

 

KYVbyBH.png

 

BmQvQI4.png

.

ibNXJFW.png

 

Wait a flogging minute. This guy writing this article is either quoting you directly or you're quoting him directly and odd that your both Mikes the pieces are coming together here. 

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