so here I am (seriously questioning) helping bring this 1982 300td 722.315 transmission back.



it does not shift up past 2nd. R, P and 1st engages just fine.



also speedometer needle seems to randomly wiggle around or sometimes just stays dead at 0mph like it the cable isnt engaged. might be tempreture related but not sure.



It did not happen on my watch, so I dont know the details of its demise, but it at 300+K it surely is quite worn and I figured id try to at least learn a thing or two in the process.

-took out all fluid (pan+tourque) was dark and somewhat sludgy but did not smell burned. new fluid filter and gasket.

-bowden adjustment moves the 1-2 shift down in rpm, but the 2-3 usually doesnt occur even well over 4000RPM.



-verified vaccum is right amount going to the modulator and holding.
disconnecting modulator doesnt seem to change the shift timing.



on second fluid flush some more sludge but fluid mostly clean, also look at the gov. gear doesnt seem worn.


took out the valve body: did seem to present signs of wear, more than just the sludge:
the ball valves esp on the main working line pressure valve had dug little mounds out of the plate inside the valvebody.(image)
I replaced w another valve body from another 722.3 trans that is known to be functional.

with new valve body it seems like the 2-3 shift almost starts engaging but then still slips and flares and fails.


so I shold still run the pressure tests, but just going down the list of suggestions on the ATSG, after bowden and valvebody next up is the gov. does that seem like a likely solution? or is this a lost cause?






any thoughts would be appreciated
in over my head again...

lowpresh.

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If the trans has 300K+ on it, stick a fork in it. At that kind of mileage and with the sludgy dark fluid you drained out, you're likely dealing with internal wear, not just valve body problems.

Since you have the ASTG manual, check your working pressures. If they're good, you may have issues in the valve body or a faulty or worn K1 clutch.



If you're planning to keep this car long-term or if you intend to daily drive it, finding a good used transmission or getting a rebuild would probably be a good idea. At the mileage on yours, if you get this fault fixed another one will be waiting for you shortly down the road. If you do get a good used one to install in the car, then you'd have an excuse to pull this one apart and do a post-mortem.

The speedometer issues are probably related to a bad speedometer cable or a seized speedometer head. The cables are a far more common fault.

__________________
Current stable:
1995 E320 149K (Nancy)
1983 500SL 120K (SLoL)

Black Sheep:
1985 524TD 167K (TotalDumpster™)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

I know 'throw it away' 'stick a fork in it' is going to be the general opinion
and trust me I am almost to that point, but until then... wondering if this is a common experience:


I checked the working pressure and it is WAY too high... 210-270 in drive, sometimes even higher as engaging in park or in reverse (which explains the check ball right on to on the working pressure regulating valve grinding out the hole in the midplate of the original valve body.

however the replacement valve body did not fix this.

I am wondering if anyone has an idea what can cause the working pressure to be this high? Ive only found one thread dealing with something similar and the fix had to do with the valve body.

I cant find a clear description of all the parts involved in the working pressure circuit, but I imagine this means the pump is indeed working but there is a block somewhere further up the , like something blocking the cooler lines? or a broken/blocked torque converter?
or is it possible this is caused by the pressure regulating system failing to engage (something to do with the working pressure regulating valve or control pressure valve).

also, i thought I understood which gear I was on, and that the problem was failing to shift 2-3.
but I am actually no longer sure.

coming out of stop or park, the engine definitely shifts once. I assumed that was 1-2 shift as it happens very early. it does not happen again until another complete stop. but I am confused by the idea that maybe it is supposed to start in 2nd and perhaps that is actually the shift into 1st that I am feeling?
if I am going 25-30mph and the RPMs are hitting the 3-4K is that 1st or 2nd?

any help /info appreciated.

I thought that the transmission modulator adjusted the working pressure. Besides the vacuum control valve on the Modulator there is a cap that is removed to get at the adjustment.

Also the Modulator Caps have been known to crack.

__________________
84 300D, 82 Volvo 244Gl Diesel

hmmmm, as far as I understood the modulator adjusted the modulating pressure which is measured by the test port next to the modulator. the working pressure test port is on the other side, passenger side, of the 722.3, and is the main line pressure of the transmission, pretty close to the main pump, supposedly not meant to be adjustable. but it is working, putting pressure in the line, too much pressure.

I guess at this point I am wondering if a bad governor can even cause such an anomaly? should I bother replacing it like the ATSG suggests? or if not, than what could be the culprit for such an anomaly? it has to be somewhere in the main circuit right? can this be the secondary pump coming online adding extra pressure? or something blocking the cooler lines making the pump push harder?

ideas?
thankx

on advice from sunvalley
im going in for the governor
this article makes it look simple


https://f01.justanswer.com/73bbchevy/9310fb65-6e18-4972-9f80-32cd9dcc03d8_governor+removal.pdf


and so far it has been



but


lowering the rear of the transmission has given me barely enough space to get the cover off


does anyone know a trick to getting the extra clearance space in a w123?


thankx
LP

never mind got it out


looks good though, which is, I guess, disappointing

and of course the governor looks totally clean and normal
which is, I guess, disappointing, as it isnt the culprit

cant find any documentation on adjusting the little plastic screws on the side of the governor??

looked in the secondary pump and the modulator and the kickdown
just to be safe while im down there, everything seems clean and normal.


The ATSG under "upshifts only in lower gear section" says "Check regulator pressure,if regulator pressure is too high,exchange centrifugal governor"

does anyone know: is regulating pressure the working pressure/line pressure (A) or governor pressure (G)?


both are too high for me
but the governor looks ok?!?


so many questions...


LP

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See the attached picture for the 3 different ports.

Was there any sort of seals on the Governor?

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__________________
84 300D, 82 Volvo 244Gl Diesel

Wow, the level of expertise on this forum blows my mind. You guys are pretty good. It is a fascinating read for a novice.

For me it is not expertise it is that I have a copy of the ASTG Transmission Manual and 2 others by other companies.

Other then Fluid and Filter Changes the only transmission work I have done is changing the B2 Piston and related parts.

Personally I think people try to do too much with out the related manuals to guide them and come to the forum expecting others to fill in the details when that is not always possible.

I think the various manuals are the basic starting points.

__________________
84 300D, 82 Volvo 244Gl Diesel

im not sure what you mean by seals?
there was an o ring for the cover that you pop

pressure tests came out too high for both the gov. pressure AND the working pressure.
I did read the ATSG and other info, which is where I got the idea that the gov. could be the culprit, and verified with someone at sun valley indeed it is likely so. but I was hoping it would be obvious when I pulled it what was wrong, but it wasnt. and I did not have a replacement ready.

under "upshifts in lower range of gears only" the ATSG suggests checking "regulaor pressure" which is not one of the three ports. but maybe regulator stands for governor? not sure... "if regulator pressure too high..." it mentions just replacing the governor. so I guess thats the only possible step left before giving up on this tranny.

When you had the valve body out, did you check the k & b springs? Have you set the modulator pressure? Is the vacuum pump putting out the correct vacuum? Is the VCV adjusted correctly ?

__________________
85SD 240K & stopped counting painted, putting bac together. 84SD 180,000. sold to a neighbor and member here but I forget his handle. The 84 is much improved from when I had it. 85TD beginning to repair to DD status. Lots of stuff to do.

I wish it was that easy


not only did I check the springs, I eliminated the valve body theory by putting in a different known-to-be-fully-functionial VB and - no luck


I also checked the modulator and vaccum system first thing, though I understand it is impossible for that to be the culprit, since disconnecting it does not affect the shift points only the quality of the shift, and without the vaccum attached it should shift harsh, but I checked it all just in case - and it didnt do it




I might be a novice, but I am thourough

.