Engine gaskets but first, in jam transmission

[Tucker the Ratsun]

Hello

ive purchased my way into a unicorn of a 4x4.

1981 720 4x4 - my first Ratsun.

Ive been learning quickly how much love this guy will need to bring him back to stable and outside of a head gasket, which was top priority after I repaired the harness, is now the recently jammed transmission.

quick inside info, the truck has been fitted with a 1992, Sd22 From a forklift, and runs great when warm, but does push exhaust into the cooling system, but that will have to wait, as the transmission locked up in reverse the other day parking at work.

is there any advice on where to start with simple solutions, observations, or history of patterns with these transmission having this issue?

 

its a bit vague of a question, but any help directing my focus would be greatly appreciated:)

 

 

[Draker]

Make sure it’s full of gl4 fluid. I’d start it and just keep wiggling the shifter and trying to get it back into neutral. Otherwise you might have to crack open the case to find the issue.

 

ive seen the shift dogs pop out because of worn components.

[wayno]

Did you buy this truck in Vancouver WA?

 

Right now I would find another transmission, below is a link to a craigslist ad of a guy in Elma WA, I believe this guy also had a diesel transmission for sale on craigslist a while back but I don't see an ad for it right now.

I believe all you need is a 71B longshaft 5spd transmission from any Datsun/Nissan 720 truck made in the early/mid 80s, you would then pull your transmission and put your front case on that good transmission, it is not that hard to do.

https://seattle.craigslist.org/oly/pts/d/satsop-datsun-15-head-h95-rebuilt/7182922588.html

Edited August 26, 2020 by wayno

[Tucker the Ratsun]

Wayno, Draker,

 

thank you, both

 

it was a simple fix and my mechanic didn’t even charge. I feel I got lucky as since I picked up the truck, it has done it once again.

but I worked it out.

a rebuild or new trans will be the future,

but it’s the head gasket I was already wondering about. 
I replaced the radiator with a perfect brass model but it won’t burp.

its clear it’s a leak in the head gasket, or by smoke from the hood, exhaust gasket. Is there a proper source for a gasket kit for sd22?

 

ps, awesome ‘link’ for that trans!! I might figure that out

 

but can I gasket this engine without removing it?...
 

im new to forums how do I post my rig? I need a photo to have an url...?

[Tucker the Ratsun]

On 8/26/2020 at 9:21 AM, wayno said:

Did you buy this truck in Vancouver WA?

 

Right now I would find another transmission, below is a link to a craigslist ad of a guy in Elma WA, I believe this guy also had a diesel transmission for sale on craigslist a while back but I don't see an ad for it right now.

I believe all you need is a 71B longshaft 5spd transmission from any Datsun/Nissan 720 truck made in the early/mid 80s, you would then pull your transmission and put your front case on that good transmission, it is not that hard to do.

https://seattle.craigslist.org/oly/pts/d/satsop-datsun-15-head-h95-rebuilt/7182922588.html

Not sure if that link is for a head

not sure if it sold 

my  truck....
Not Vancouver,

but it was registered in Camano island.

to be honest, I bought a bomb, but I’m not telling stories yet, just asking questions.

can I replace the head gasket in an sd22 first time go? Is an in-line4 diésel this straight forward? I’m pretty sure I found gold, but I’m buying tools as I go;)

im serious,:) what’s the best/reasonable gasket kit for 94’ sd22? Forklift

 

 

this truck is too cool:)

 

how do I URL a photo?

[4perrev]

Tucker. you can replace a head gasket without removing the engine, but sometimes getting the exhaust and intake bolts out are a pain in the a$$.  Might be worth pulling the entire engine out and doing a complete rebuild.  That way you will know it's all good to start with.  There is a picture how to on the main page that will show you how to do pictures.  don't use PHOTBUCKET as they suck and it will make you pay.  Wayno is the diesel guy from what I understand?

 

Welcome to the house!!

[wayno]

That link is to a head, but that guy also rebuilds and sells transmissions and has had a diesel transmission for sale in the recent past that was on Craigslist for a long time, not sure if he ever sold it as there are not a lot of diesel 720s around anymore, you appear to have bought one of a handful of 4wd diesel conversions in this country, Australia has a lot of factory built 4wd diesel trucks.

Yes you can change the head gasket while the engine is in the truck, when you pull the head you need to pay attention, there is a o-ring of sorts and the head gasket, you need to put the new o-ring in when you install the head gasket, you leave that o-ring out and you will be pulling it apart again.

Getting to the nuts on the underside of the intake/exhaust can be difficult sometimes, but I have never had an issue removing them myself in a 720, sometimes that rear exhaust manifold nut is hard to get to, just spray some PB Blaster or the like on the threads of the studs you can see before you start.

Another thing to keep in mind is when you remove the injection pump lines it will likely be difficult to get the diesel engine started, prime everything before attempting to start it as getting that diesel starter hot from turning it over long periods of time is hard on it.

I am curious, is the shift lever popping out of position when it jambs in a gear?

There are lots of gasket kits on ebay, but you want a kit with a metal head gasket and intake/exhaust gasket, you might be able to get one from Nissan, part# A0101-V062H, these Nissan gasket kits are not cheap, this kit I have the number for is for the whole engine, you only need a head gasket kit though, I could not find the o-ring to take a photo of, as I recall it is an orange color.

Edited September 6, 2020 by wayno

[Tucker the Ratsun]

Wayno,

that is all awesome information!

i have a good direction, thank you much!

 

ill check out that mystery o-ring and see if the kits include it. I’m feeling a rebuild on both, trans and engine would be prudent.

 

so when it jams, (also, the other day it was like revers disappeared..But it came back after 5 mins...) but the shifter bends at the joint where it connects to the transmission body. ... (still learning terms) 

 

its also difficult to find first and second, even shifting while not moving. It feels like it’s not lined up right, and cracking it open with be the only true way to trust it.

 

[wayno]

Is the shifter loose/sloppy?

It is supposed to have this plastic thing on the ball that goes into the shift mechanism hole, if that plastic thing is gone shifting could be a bitch.

Some of the 5spd transmissions had tall ears where the shift lever goes, this could also be an issue if that plastic piece is missing.

You can see the ends of 2 shift levers below, one has a short finger with the plastic piece on it, the other has the long finger but is missing the plastic piece.