No 1st, Reverse is great still... any ideas?

[Brandons]

I havent actually taken it out on the road yet.. part of the fact of no exhaust.... but i plan on taking it out tomorrow with or without. When i had the vacume line off it seems to go alright... But with it on, i get no drive unless i press the gas up to about 2500rpm, then it slowely moves. Without vacume line, engages after a couple seconds and then goes, or has a slight delay then clunks into gear. I do wonder if the vacume modulator is ok, it didnt seem that great when i was playin around with it. The TV spool was a bit of a pain to get out, had to do a bit of wiggling before it would come out.

On a bit of a side note, i usually got a CEL with the exhaust on,.. for the 10 minutes without exhaust on i happened to get no CEL at all...

Im also wondering.. i lost alot of fluid when i pulled out the TV spool.. i think i totally forgot to add more.. there was some on the dip stick when it was off (between the two holes), enough that i could get it off the ramps at least. I shall check that.

Another addition.... the fluid is still not see through this time (while in the 3" by 4" by 8" container).. only a week with new fluid and its already dark and opaque (non see through.. translucent is probably a better word for it).

 

[Brandons]

Alright tonight im taking it out to a friends place (test drive, and to hang out for a while).. In about 10 minutes im gonna go top off the fluid and head over.

Ill try and post back any changed results.

 

[Glacier991]

when you changed fluid, did you do a flush and fill using about a dozen quarts, or just dropped the pan and then changed it that way, using about 4-5 quarts? A pan drop change does not change fluid really, it merely dilutes old by half with new. You'd need about 4 or 5 pan drop changes to really have changed the fluid akin to having done a flush.

 

[Brandons]

I see. i just dropped the pan. I was more interested in seeing any shrapnel then anything. How exactly do you do a flush?

(also no difference with the drive tonight.. just kinda neat driving with no exhaust lol)

 

[Glacier991]

I stickied a thread on flushing. I would also suggest you go ahead and replace the modulator. They should cost no more than $20.

 

[Brandons]

I shall then, i have monday morning off to install it as well. Ill look into the flushing thread later since im going to start school project.

Do you think driving it will damage anything?

 

[Glacier991]

drive it a day or two in whatever manner works best... no vacuum hookup works best? so be it. Do it. Ideally try and fix it before you drive it a lot not operating correctly though.... but since you say it seems to operate "reasonably" ok w/o vacuum line, that seems ok by me, for now.

 

[Brandons]

Yeah. It seems to do just great (next to of course the high shift points that come with no vacume) except when putting it into drive... Once i feel it clunk into gear, no problems after that. Of course i cant drive it with the vacume line on though barely moves in drive with it on.

I plan on getting this thing fixed, hopefully the vacume modulator does it (knocks on wood). Im having a slight lack of time lately, only had one day off since half way through october, I tend to not like to do any repairs after work since id probably not be totally with it then.

 

[Brandons]

Well today i put the new vacume modulator in, i go to test drive it.. nothing.. i even put the vacume line back on when i tested it.. so back to square one. In fact after i got it in my driveway (to add to a nice day my tire came off my wheel) it had even more trouble engaging into drive. im seriously hopeing this isnt turning out to be a rebuild... god i get chills thinking about the last 3 ive dropped.


Also my daily drive is about 5km total of driving lol

 

[Brandons]

Alright, i took the truck to see the doctors (Mister transmission) today and the final conclusion was it needed to be dropped. They seem to be hinting on it being the fact i had ran it without the vacume line on for a while, something along the lines of not providing pressure to the torque convertor. I wasnt very confident in them after hearing this.

When they went to put it in the shop it would not go into drive for them. The fellow tried and tried but with no drive.. So we pushed it a bit so they could back it in and they did the free inspection. They also noted that a front seal could be leaking or pump seal.. though i havent noticed any leaks lately at all, i think they saw the fluid since i changed the cooler lines because they were leaking.

They let it coast out of the shop, park it, and kindly wish me good luck on getting it home. Next thing you know i took the vacume line off (they had it on for testing) and plugged the octapus and next thing you know, a couple seconds of a bit of gas, it goes into gear. I put the emergency brake on, close the hood, get back in, and go, and now im home.

So im at the point were im quite lost. Any advice at this point? Should i take the transmission to these guys?

So im at a total loss of what next.

 

[Glacier991]

I am at a loss here. The fact you have seemingly "normal" operation with the vacuum line off seems to validate that the mechanical "innards" of your transmission are ok. You removed the tv and cleaned it, made sure it moves freely in the bore, replaced the modulator, and same symptom. So clearly somehow the activation of the throttle valve (tv) is what is causing your no go. Next step were it mine would be to drop the vb and rebuild it.

Here is a theory. Bore 203 (2-3 shift but used in all gears) gets energized by vacuum to the TV. You could have a catastrophic leak there, and with the TV activated lose all pressure via that leak. Without it leaking, you don't get that failure and at least have "some" pressure. A transmission pressure gauge would be a valuable addition to our arsenal, I bet it would show up as non existent line pressure with the vacuum line attached. I'm thinking you have a VB problem....but...

Failing that, I will be honest though you have pretty well exhausted my knowledge base here. Extremely perplexing. If you don't want to do a VB rebuild and just try an A4LD VB in place of yours we might work something out. PM me.

 

[Brandons]

I am actually quite interested in a VB rebuild. Since im pretty much going to park the truck for a bit, i may as well give it a try.

Heres a bit of an update..
- when cold it takes a couple seconds to engage
- when hot it takes about 10 seconds as well as revving the engine a bit (probably 1500rpm)

the situation is getting worse though and im unsure why. Ill look into rebuilding the valve body.

Thanks for all the help Glacier, really helped me get through all these problems.

 

[Glacier991]

Ok well let's rebuild the VB and reseal the low/reverse servo. Before you do the rebuild be sur and flush the tranny so we start with nice clean fluid. No sense in gunking up a rebuilt VB. I am still thinking your trannie is mechanically fine.

 

[Brandons]

Sounds good. I'll look into how to flush it since im not quite entirely sure of the procedure (since i have my not so bright moments). Digging into these things kind of scares me.

 

[Brandons]

Here is a theory. Bore 203 (2-3 shift but used in all gears) gets energized by vacuum to the TV. You could have a catastrophic leak there, and with the TV activated lose all pressure via that leak. Without it leaking, you don't get that failure and at least have "some" pressure. A transmission pressure gauge would be a valuable addition to our arsenal, I bet it would show up as non existent line pressure with the vacuum line attached. I'm thinking you have a VB problem....but...

I just read your thread on a transmission pressure guage, and im going to look for a guage, since this would help a lot.

(i also noticed you added that part when i was re-reading the thread, sounds good to me )

 

[Brandons]

alright ive been looking at this guage on ebay

http://cgi.ebay.ca/Automatic-Transm...ryZ43989QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Does it seem alright? I really only need to tell if i have pressure in drive right?

 

[Glacier991]

That's perfect.

 

[Brandons]

Sounds good, just need to get it some how.. hopefully i can get it through my friend who has an ebay account... unless we can buy it without being through ebay..

 

[Brandons]

alright im still looking around for the pressure guage, the one on ebay is a bit too far shipping wise. Im thinkin princess auto may have it, so im gonna try there, if not i might just go ahead and do the VB rebuild...

 

[Glacier991]

I recall reading that accidentally installing a C-3 transmission modulator on an A4LD can cause a no go condition. Just thought I'd throw that into the mix here. This one really has me puzzled.