72 cutlass, 350,, th350 tranny. i parked the car for about a week, in that time i put spring helpers on an already saggy suspension, suspension feels good, just sits low...new shocks....i also hooked up the detent cable, dont believe its been hooked up since ive had it.....when i went to drive the car, when i take off from a stop, there a weird jerking//shuddering, feels like its from the rearend, but that doesnt mean anything.....i took the spring helpers out, still does it,,could it be my springs are shot, and giving the wrong geometry to the driveshaft/tranny/and rearend? or is maybe the detent doin something weird..."noise" feels like rearend is shot, chipped gear or something,,but its smooth, and this problem only occurs at o-10mph, maybe less on the speed, but only on acceleration...i didnt try to floor it, but it feels like its not as responsive, (tranny slipping), fluid smells good, correct level....help, its up in the air now, but havent had the time to tear into it.....thanks guys, also, what vacuum line is the vacuum advance on my hei supposed to be attatched to? carb or somewhere on manifold........................

 

worded the vacuum question wrong but im sure you get the idea ;-)

 

Shudder could be sticky/frozen u joint(s) they can be stickier after sitting for awhile.

Hei can go to ported or manifold vac. Some consider ported vac an emissions band aid. Mine is to manifold vac

Springs are under $100 and are available at any auto parts store. Helpers just mask weak springs

IDK what a detent cable is?

 

your detent cable is the kickdown cable........ive thought about the uoints, good call,,,,wont have time to look it over till tomorrow and yeah, i got new springs on the way..............

 

When was the last time you changed gear oil or checked it's level? If the car has a posi rear end it could be the G.O. additive is worn out and you're feeling the clutches binding.

 

I would disconnect your detent cable to the way it was and drive it again to see if your problem goes away. Ujoints also come to mind. The vacuum as stated above can be either manifold or ported, basically personal preference.

 

Even if your springs are riding low, that shouldn't affect the aspect of the differential to the drive shaft. U-joints are designed to compensate for any slight variances there.

 

Thanks guys, after work in the morning, I'm gonna do some inspecting, now if it happens to be the kickdown cable, WHY? is there something wrong with it? What is the correct adjustment procedure? When I was driving the car with the detent hooked up, I'm not sure I tried to c if the kickdown was working,,,I was to worried bout what I was feeling in the rearend, or wherever it was coming from.....what should I look for, for a correctly operating kickdown??

 

O,,,and the rearend is a diff,,non-posi

 

UPDATE;;; unhooked te kickdown, drove i, and after it warmed up, it started the problem again, but its getting worse, and tranny is slipping, and having a har time up shifting.....so i narrowed it down to the tranny. i take it its time for a rebuild? or is ter anything else i can look at??

 

Now that we narrowed down it was nothing you changed. Double check your fluid level.

Let's look at the vacuum modulator, lines, and vauum source. Make sure your not leaking fluid there, and all of the lines are serviceable.

 

There is a vacuum canister behing the passenger kick panel, what is it for?? Whille messing around, I noticed it was unhooked, so I hooked it back up....also, are there any elecrical connections on the th350 tranny?

 

I'm at work, or I'd check it out, but there are 2 vacuum lines coming out of the firewall, behind the distributor...they were dryrotted, so I cut the dryrotted sections out, and never fixed it,,one went to the vacuum canister on firewall, not sure where the other went, but I know it didn't go to the modulator on the tranny....could this lack of vacuum be causing my prob??? Gonna check it out in a few hours when i get home....

 

A large vacuum leak will effect a lot of things, including the transmission. No electrical connections on the T350.

 

K, I checked those vac lines, and I did fix them, so no vac leak...I put Dr tranny shudder stop, and a bottle of trans x in, and the shuddring stopped, but drove nine miles or so, and the slipping is getting worse.....so in total, trans was fine, and now ive drove about 25-30 miles, and it'll barely pull itself up hill...I did run low onfluid once, and had to slip it into a parking spot, fluid doesn't smell burnt, but is it possible I burned up my torque converter...this car has always been takin care of, I've had it about 5000 miles, and tge previous owner changed fluid and filter before i got it...could the filter be installed wrong??

 

Could it be your fluid level? Check it hot, in park with the motor running.

 

Fluid level perfect, and in good condition ,

 

Those lines are for your air conditioning. If the blend is not working on the dash selectory, it's probably because your dashpots are disconnected or hoses dry rotted.