722.1 Transmission help???
 

I have an issue, a rather bad one...I was letting my buddy drive my car to get more driving experience...I was telling him, don't be afraid to floor the car and the kick down switch under the accelerator...It seemed like he was playing speed racer in it...didn't think much of it...I then noticed the speedo needle jumping....odd...I went to run my mom out and the transmission is acting up....just driving normally it drives fine but out of the blue it will drop the gear and the speedo needle will go to 0....

I unplugged the kickdown switch, problem persists, fluid level is right at the max mark, took in on the freeway....no change...I finally just parked it, to dark to do anymore investigating..

Its an odd issue because, it feels like it does when you hit the kickdown switch to drop a gear but your foot isn't pressing the peddle down to hit the kickdown switch....maybe the solenoid is sticking?

OK I'll use my ten thousandth post on you

When you say drop a gear do you mean goes into "neutral" or goes from 4 to 3 (say)?

If the gear goes down a gear then you have governor related trouble or as you say kick down related trouble - because the speedometer drive seems to be a related issue it seems to me that summit's slipping back there

Perhaps your kick down solenoid is stuck. Did you try to tap it?

Exactly, it drops from say 4 to 3 3 to 2 2 to 1 it does it in every gear.


I am also thinking the kick down is stuck or maybe my make shift bushing popped out.....I will be crawling under the car after coffee and checking both..

If the kickdown were stuck, I would have thought it would be revving very high through each upshift on acceleration as well.

If the solenoid wasn't disconnected, I would wonder if perhaps the switch had got something stuck in it that was making it engage randomly.

A long time ago I recall (on another list) a post by someone whose trans mount disintegrated and, in concert with a worn shift bushing(s), caused behaviour like this from the transmission actually moving under the car.

Thing that worries me the most is the speedo dropping to zero - sounds worse than a stuck solenoid to me

I have a new mount under the trrans, I have replaced all the shifter bushings but one...

The speedo dropping is what has me worried also, its very odd.....the kick down is disconnected but it could be possible the valve is stuck just enough to not let pressure build up in the trans.....I am just very worried....there is no way I can afford a new trans and this one was just replaced in 2002..

Does the transmission behave the same way if you leave the lever in S?

If exterior inspection comes up with nothing, you could do worse than add a can of Seafoam, to see if that makes any difference.

If it's any consolation, the governor is accessible without removing the transmission, but the tail cone has to come off.

Well I checked all the bushings, they are all there, linkages all look good. I wired the kickdown plug, jumped underneath...and tapped the wire to the screw....and you can here it clicking....went for another drive and same issue....it appears now that it is revving up very high and not shifting until I take my foot off the peddle...then it will some times up shift...

I believe I tossed my old solenoid as it was dead so I can't switch one in....I am waiting for the manifold to cool down and then I will pop the bowden/pressure rod off and see if by chance it needs adjusting..

As I have 0 funds to toss parts on it....I will pull the seats up for the euro and switch the plates over and drive that....of course it has no fuel...so will need to siphon fuel out of the silver guy....lord I didn't need this...

hmm good question, I put the shifter in S to attempt to kick it up or something but can't remember if it did anything different..

I have almost a full can of trans X in the trunk...I was thinking of draining some fluid and tossing that in....would it suffice?

That is nice to know...

You have a control linkage going to the transmission?

The only 722.1xx transmissions I am aware of are vacuum control only, no rod or cable.

What model is your transmission, exactly?

Edit: I was forgetting you have a '78 like my coupe, so I guess no vacuum control on the transmission and a control rod.

But I did not think those were 722.1xx. I have never looked at mine, to be honest.

I think your trans might be a 722.0.

I found this post in the archives, by Steve Brotherton of Continental Imports (transmission guru).

Not sure it will do anything for you, but it seems to clear up the misconception that your model of trans had no modulator adjustment:

The fixed modulators on early diesels are have a straight screwdriver adjustment under the 17mm cap nut (think its 17). As with movable modulators the key to the proper pressure is the eventual protruding length the device imparts on nthe valve inside the trans that it applies. A significant flair or soft shift can arise from putting a sealing washer under the device when screwing it into the trans. As the total length is the criteria adding the washer messes it all up. Move it in for harder shifts and out for softer. This trans is designed to have control presure control shift pressure and if no one has screwed the mod up then the proper mechanism for increasing shift strength is to make it shift later.

Also a follow-up from the OP Steve was answering:
Thank you all very much. I think it is all starting to make sense. There is a modulator adjustment access at the tail of the transmission housing on the passenger side just like C32AMG said. It has a 17mm cap.

Check the nut on the trans to drive shaft flange.

The 722.0s were three speed units fitted to V8 engines

However the 722.117 and 722.118 started life with rod throttle linkages (like most 722.1s) and an adjusting screw as described above instead of a vacuum dashpot. Later the rod linkage was dropped and they went "vacuum only"

Correct, I will double check but I believe mine is a 722.118 and it does have the rod....

I installed the bottle of trans-x.....at first appeared to be working better but still the speedo was droping to 0 and then back up then jumping around...

I drove it around some more and its like it is now wanting to stick in a lower gear and not shift back up..

So now I am going to but some of the euro back to make it drivable so I have a car, until I with the help of you guys an help me out..

I had the unwillingness to shift up problem with my '80 300td, with a .117 installed.

It was a sticking governor.

i have a 722.120, has both vacuum modulator and control -rod-

Forgot to grab the number...but no change and now I have the euro back together good enough to drive.....man I forgot how power the euro had compared to the US...i can get up to 80 in no time...place can climb a hill at 65...where as the 78 had me going at 45 if I was lucky...

Well I guess next thing, to do is to start researching how to get to the governor, tools that I will need, where to buy one etc..

If anyone has a DIY or the FSM procedure...please share...

Perhaps the governor being bad, has been causing the hard shifts that I would feel, especially when cold...and maybe my burnt fluid issue..

That was factory fitted to the W116 300SD

Start from about post #27

http://www.peachparts.com/shopforum/diesel-discussion/304903-722-118-automatic-transmission-rebuild-monster-diy-2.html

However before you pull it to bits consider this

1) It is ALWAYS best to make some pressure measurements before you pull things to pieces (if you don't want to start a big project!)

2) When you remove the tail cone section from a 722.1 transmission you really need to make sure the shim position of the gear set is correct => everything is measured from the back end. If you just remove and replace there is a danger that one of the little needle roller bearings falls out of whack in the gear set and you'll end up buggering more stuff up!

Ah crap....this is going to be one of them pita projects....

I would take pressure readings, but we know there is something messed up in the tail end of the trans, so the only way to figure that out....is to take it off and inspect whats inside correct?

There is a 83 300D and 300SD in the yard, any chance the tail end of one of those trans will bolt onto mine?

I have never ever ever done any type of transmission work, and I am so afraid i will bugger it up and be forced to buy a new trans, that I can't even afford...

The '83 300D and the 300SD (assuming W126) should have 722.3s in them - so you then need torque converter + bowden cable + throttle linkage bits

The problem is you are now at one of those cross roads

Is the speedo related or separate? (Probably related but we don't know)

Could it be something simple we haven't seen yet?

You are best off looking and measuring at this stage in the game.

Well I don't think I will be going in seeing what is wrong with the trans, I suppose I can get the stuff to measure the pressure..

I just checked and the governor is priced at $688.00.....I really really believe that the governor is the issue...

Since I got the car running about three years ago, I had a big issue with high reeves and hard shifting...I cured it a bit with linkage adjustment, correct fluid level and the pressure rod bushing....but I still had a hard 2 to 3 shift...the trans was rebuilt in 2002 and I remember the receipt(lost in fire can't check now) saying that all the bands, clutches and gaskets were replaced...the shop never changed the rotted mount, missing bushing or bad NSS....I am now thinking the governor was the issue, requiring the owner to look for a rebuild...

So to the cross rods.....what to do with the car? Look for the correct trans? upgrade to a newer non turbo auto? Manual setup?

I don't want to junk the car, as I do really like it....but she burns oil, suspension sags...calipers need rebuilding...etc....

I hate these cross roads :cry3:

Bummer Jay

i guess there'll come a time we'll all have to face this tough choice

Ok but bear in mind that when I said the problem on mine was the governor, nothing had to be replaced. It was sticking and the shop freed it up. The only part was the gasket for the tailshaft and the shop made one as they got some stupid price quoted when they tried to order one.

Even if you do need a part, I am sure someone can come up with a used one.

Just to confirm: your car has a vacuum modulator, or the mechanical one I posted about earlier in this thread?

Mine is the mechanical one.

The transmission has a few other issues too....the shaft the pressure rod attaches to that goes into the trans...is also leaking fluid and I read that the trans needs to be disassembled to replace that...and the fluid is burnt again....I am assuming a stuck governor wouldn't cause this...

I hate to make a decisions like this, but it may be time to let this ol silver girl be laid to rest...

She burns a quart of oil every 300 miles....has very bad blow by....I was going to try to replace the valve stem seals to see if this cured this but have read it is not likely the issue....

I won't be getting any funds for a long time, so I have time to decide the course of action...

Danger! Danger! Danger!

This is a forum so there will be a lot of arm chair diagnosis - that's OK up to a point but at some time or other someone actually has to go and take a proper look and ideally make some measurements.

Cooljjay you've already talked yourself into doom and depression - take a deep breath and go have a look see

hehehe you are so true!

I will go and take a deep breath...

My two main things putting in my doom and depression...is I have never worked on a trans before! and then....the oil burning going on in the engine...

Then the power difference between my euro and her...here lately, I have just noticed my oil pressure not even getting up to 30psi when idling and when started not even wanting to peg...the euro pegs at 4 right away and stays at 40.....I am getting to a point, that it feels like I am just putting band aid after band aid on her....I feel I really need to tear both the engine and trans to pieces and put it together correctly..

I remember you stuck with this car well after most people would have thrown in the towel, back when you were trying to get it started.

There is a line somewhere between stubbornness and insanity that we sometimes have to cross in order to drive these old cars.

Time for you to cross it anew, as it relates to pulling the tailshaft off and having a look. You have the unique advantage of Stretch being here, who has BTDT.

Perhaps buy a part a car with good engine and trans? I also mess with oldDatsun Z cars. We trash cars that would be considered gold in the Z world. I have a late 84SD that is almost whole that I'm thinking of selling. Too many projects. Good engine, no reverse.

Your right....I will most likely pull the tail end and see whats up....damage is done...what else can be damaged right? Well besides the car falling on my head :P

That is another option I was looking at...finding one with a good engine and trans..