Dang thing just ate ANOTHER transmission!

Dealing with all subsystems specific to the diesel powered Datsun-Nissan 720 pickup trucks.

Moderators: plenzen, Nissan_Ranger

Post Reply
Dale
Posts: 19
Joined: 11 years ago

Dang thing just ate ANOTHER transmission!

#1

Post by Dale »

Just ate my 2nd transmission, shifted into reverse in my driveway, clutch fully depressed, released clutch and... engine bogs, no movement. Put in neutral, released clutch and... truck goes forward. Stuck in 1st. Just like the last one got stuck in 2nd. And the previous owner had indicated he had several do the same frikkin thing...

Not sure I can keep feeding transmissions to this hungry beast.
plenzen
Posts: 890
Joined: 16 years ago
Location: Cochrane Alberta Canada

#2

Post by plenzen »

Not sure what to tell you.

Unusual for it to "consume" otherwise healthy transmissions.

Next trans you get try this.

Drain oil and fill to operating level with auto trans fluid.

Jack rear wheels and start and run through all gears for a few minutes

The auto trans fluid is a great cleaner and will wash the inside really well. It cleans out all the small lines/grooves on the balk rings and makes them grip again as well as washes out all the brgs, bushings. thrust washers, etc etc.

Drain and fill with a good quality synthetic trans oil like Royal Purple, Amsoil or Red Line.

( I prefer the Red Line myself )
Retired Pauly
Problem with being retired is that you never get a day off.
1987 D21-J SD25 KC
KJLGD21FN
Dale
Posts: 19
Joined: 11 years ago

#3

Post by Dale »

I can't even find a local trans shop that will touch it... I'm getting the idea these things are junk. This last trans lasted about 2000 miles. Anyone want to buy the clunker?
plenzen
Posts: 890
Joined: 16 years ago
Location: Cochrane Alberta Canada

#4

Post by plenzen »

That's unusual that no trans shop will deal with it. The transmission is essentially the same as the gas model. The bell housing is the biggest difference and in fact there are some members here that have successfully converted the gas trans into the diesel.
The parts kits are available for it and it is really no different than any other manual 5 spd transmission.
I think perhaps you should talk to a different shop.
I had no issue whatsoever getting mine rebuilt at the very first shop I went to.
As for them being a POS I would have to disagree with you on that as well. The early models had a weaker front brg that would start making noise after a few hundred thousand miles, but, I believe that Al addressed that issue in a link to the fix for that with an alternative brg number.
Get it built by someone that know what they are doing and it should give you years of loyal service.
Retired Pauly
Problem with being retired is that you never get a day off.
1987 D21-J SD25 KC
KJLGD21FN
Nissan_Ranger
Posts: 270
Joined: 17 years ago
Location: Canada

#5

Post by Nissan_Ranger »

If they don't want to touch it, PERFECT!. It's the classic mark of a business that wants to get easy money and do nothing for it. Good one to stay away from as they usually combine their lack of ambition with a lack of true skill...

N_R
The old 'six gun' was as popular as the cell phone in its time and just as annoying when it went off in the Theater.
charmalu
Posts: 166
Joined: 13 years ago
Location: Soquel, Calif

#6

Post by charmalu »

That is really strange with the problems you are having with these 5-spd boxes.
This Friday Oct 18 will make 32 years ago I bought mine. we are just about to roll over 479K miles. the only problem I have ever had, is to replace the input shaft bearings which seem to be the main problems these have.

First time we did all the Bearings and that was some where around 200K then just replace the Input and Counter shaft this past June.

Except what was in it when factory new, it has run Amsoil Synthetic for the major portion of it`s life. Don`t know if it made any difference in longevity, but Makes me feel good. :>)

Charlie
82 Datsun KC 483K lost #2 cyl blowing blue smoke :cry:
83 Nissan LB 134K SD-25 as of 10-21-13
78 240D Mercedes $300 Parts?
80 240D 360K
80 240D Parts? $750
82 240D Parts? $440
84 300SD 270K
85 300D 363K
86 Ford F250 6.9 Diesel 221K
User avatar
asavage
Site Admin
Posts: 5431
Joined: 18 years ago
Location: Oak Harbor, Wash.
Contact:

#7

Post by asavage »

charmalu wrote:Except what was in it when factory new, it has run Amsoil Synthetic for the major portion of it`s life. Don`t know if it made any difference in longevity, but Makes me feel good. :>)
I am a big booster of synthetic lubricants, and I run AMSOil in all my stuff here.

The FS5W71 isn't a real heavy-duty trans, and the diesel's torque does seem to make the pre-'85 front bearings die (from my '82 when I bought it):

Image

And reverse gears break if abused in this trans.

I've had the lockup problem on ONE of my 720s, and it was that way when I bought it. It's an internal shift linkage problem and that truck was abused (I bought it from college kids).

However, if you change the gear oil regularly, and don't drop the clutch in reverse, I think they hold up rather well. Most people never change the trans or diff oil.

AMSOil is worlds better than the OEM 1981-era gear lube.
Regards,
Al S.

1982 Maxima diesel wagon, 2nd & 4th owner, 165k miles, rusty & burgundy/grey. Purchased 1996, SOLD 16Feb10
1983 Maxima diesel wagon, 199k miles, rusty, light yellow/light brown. SOLD 14Jul07
1981 720 SD22 (scrapped 04Sep07)
1983 Sentra CD17, 255k, bought 06Jul08, gave it away 22Jun10.
charmalu
Posts: 166
Joined: 13 years ago
Location: Soquel, Calif

#8

Post by charmalu »

I guess I have been fortunate with this transmission, or it is my driving style. with 479K and only two times in those miles I had to replace the bearings says something.

I read in another thread where you linked in the 720 Nissan forum, a guy mentioned to maybe change the CS bearing every 30K miles. seem over kill.

I bought a SD-22 and 5-spd trans off CL from a guy in Vancouver, Wa. last April. Came up from Santa Cruz in may in our Mercedes 240D, and picked up the 5-spd. then in July came back up in the 82 KC to bring back the engine.

(Daughter lives in Tigard, or. and Grand Daughters 4th BD and July she had a Baby boy.)

Eng/trans only has "110K miles" HMMMM... ok. main shaft brng looks worse that the one you posted up above.

Soaked the cylinders in marvel Mystery oil for a couple weeks, slowly turned eng over by hand a few times. (eng sat for a few years) cranked her over with the injectors out. got things together, and when she belched to life, had so much smoke thought the barn was on fire. after it cleared out and a couple more tries got her to run, but a bit rough. (I did adjust the valves)

Let her sit and a few days later went back to try again, but this time she pushes the dip stick up and oil comes out. :>/. so now I`ll get to her later next summer. too many other car projects to finish up on now.

Iam a Preferred customer with Amsoil, and the wearhouse is about a mile from my Daughters. so Iam always heading back to Calif with a few cases of stuff.

Charlie
82 Datsun KC 483K lost #2 cyl blowing blue smoke :cry:
83 Nissan LB 134K SD-25 as of 10-21-13
78 240D Mercedes $300 Parts?
80 240D 360K
80 240D Parts? $750
82 240D Parts? $440
84 300SD 270K
85 300D 363K
86 Ford F250 6.9 Diesel 221K
User avatar
asavage
Site Admin
Posts: 5431
Joined: 18 years ago
Location: Oak Harbor, Wash.
Contact:

#9

Post by asavage »

I'm an AMSOil Preferred customer too (costs only $20/year). Have been for a couple of decades.

I wish I'd known you two years ago; my father passed away and I sold his '77 240D on CraigsList for $800. Ran perfectly, most everything worked perfectly including A/C, but a really beat-down looking car. He never washed it, ever. Didn't believe in creating an attraction for vandals. That was Dad.

I worked in Tigard for a couple of years.

Nachi's a good Japanese bearing, but I prefer FAG or BCA. I've installed Nachis though.
Regards,
Al S.

1982 Maxima diesel wagon, 2nd & 4th owner, 165k miles, rusty & burgundy/grey. Purchased 1996, SOLD 16Feb10
1983 Maxima diesel wagon, 199k miles, rusty, light yellow/light brown. SOLD 14Jul07
1981 720 SD22 (scrapped 04Sep07)
1983 Sentra CD17, 255k, bought 06Jul08, gave it away 22Jun10.
elminero67
Posts: 143
Joined: 14 years ago

#10

Post by elminero67 »

For those that had transmission failure, were there any warning signs-or did they go out without warning?
User avatar
asavage
Site Admin
Posts: 5431
Joined: 18 years ago
Location: Oak Harbor, Wash.
Contact:

#11

Post by asavage »

There's usually a LOT of warning. Whining in all gears except 4th is the big one. The drain plug is magnetic and will be covered in CHUNKS of metal if the bearing gets bad enough.

Eventually, the gears are ruined and replacing the bearings will not quiet operation.

This in the input shaft as I got it in my first '82 720 SD:

Image
Regards,
Al S.

1982 Maxima diesel wagon, 2nd & 4th owner, 165k miles, rusty & burgundy/grey. Purchased 1996, SOLD 16Feb10
1983 Maxima diesel wagon, 199k miles, rusty, light yellow/light brown. SOLD 14Jul07
1981 720 SD22 (scrapped 04Sep07)
1983 Sentra CD17, 255k, bought 06Jul08, gave it away 22Jun10.
charmalu
Posts: 166
Joined: 13 years ago
Location: Soquel, Calif

#12

Post by charmalu »

elminero67 wrote:For those that had transmission failure, were there any warning signs-or did they go out without warning?
First time I had a problem we were coming home from Salt lake City back to Calif. some where in the middle of Nevada a whine started to develop. took it to my buddy and he said it is a bearing.

This last time (replaced bearings in June/July) I started to suddenly hear a different sound like it was in the dash on the Center right. Kind of like air blowing through the vents sound but not loud. this went on for a couple weeks, and finally I used a 3/8" extension from my ear to the shift lever in each gear. I could hear a thunk thunk sound in a couple gears. but only through the extension.

I drained the oil, and it looked like silver paint. I had replaced it 25k miles before.

Now this 83 Nissan I just bought is making the same sound. :>/

Take a bearing and wash it in some gas. then spin it in you hand, that dry sound is sort of what Iam hearing.

I haven`t drained the 83`s trans yet. maybe tomorrow.

Charlie
82 Datsun KC 483K lost #2 cyl blowing blue smoke :cry:
83 Nissan LB 134K SD-25 as of 10-21-13
78 240D Mercedes $300 Parts?
80 240D 360K
80 240D Parts? $750
82 240D Parts? $440
84 300SD 270K
85 300D 363K
86 Ford F250 6.9 Diesel 221K
charmalu
Posts: 166
Joined: 13 years ago
Location: Soquel, Calif

#13

Post by charmalu »

asavage wrote:I'm an AMSOil Preferred customer too (costs only $20/year). Have been for a couple of decades.

I wish I'd known you two years ago; my father passed away and I sold his '77 240D on CraigsList for $800. Ran perfectly, most everything worked perfectly including A/C, but a really beat-down looking car. He never washed it, ever. Didn't believe in creating an attraction for vandals. That was Dad.

I worked in Tigard for a couple of years.

Nachi's a good Japanese bearing, but I prefer FAG or BCA. I've installed Nachis though.
I bought the first MB in 97, now they keep following me home. Like a puppy Dog, can I keep it? :>))
I always want to buy every old 80`s Diesel I see, trying to save them all.
77 was the first year for the W123.

The 240`s are a simple car with everything being manual especially the Climate Control, crank windows and a 4-spd.

We won`t be back up to Tigard till maybe May or June.

Charlie

Charlie
82 Datsun KC 483K lost #2 cyl blowing blue smoke :cry:
83 Nissan LB 134K SD-25 as of 10-21-13
78 240D Mercedes $300 Parts?
80 240D 360K
80 240D Parts? $750
82 240D Parts? $440
84 300SD 270K
85 300D 363K
86 Ford F250 6.9 Diesel 221K
Post Reply

Who is online

Users browsing this forum: No registered users and 5 guests