Team Camaro Tech banner

1 - 20 of 20 Posts

·
Registered
Joined
·
76 Posts
Discussion Starter #1
I am having a problem which I thought might have been a carb accelerator pump issue, but now I'm wondering if it is a transmission problem.

When the car is warm, if I accelerate, it seems like more often than not, the engine RPMs will increase, but I don't feel any additional power or acceleration. If I slowly hit the gas, then I do accelerate slowly, but if I am slightly aggressive or want to really accelerate to pass a car, the RPMs increase but the car doesn't go any faster. I'm pretty sure it's not the accelerator pump anymore, because I'm pretty sure it's not a hesitation or bog.

Does this sound like a transmission issue? If you need more info, I'll tell you all I can, but I'm not sure what direction to go in so I don't know what other signs or symptoms I need to look for.

I bought this car early this year and it hasn't always done this. The transmission looks clean so I thought it would have been a recent rebuild, but I know the previous owner put in a new engine after blowing the last one so who knows what kind of damage has been done to the transmission.

Should also mention that the transmission leaks but I'm not sure from where (fluid looks good though)... it's always leaked but it seems like it's leaking more now than it did before. I'm thinking I might need to hurry up and swap in the 700r4 I was planning on...


I also think I may have answered my own question....
 

·
Registered
Joined
·
3,765 Posts
To be honest, it sounds like the tranny is worn out. You mentioned that the tranny leaks. Before you try your hard power accelerating, are you making sure that the tranny fluid is where it's supposed to be? Low fluid levels will make for a slipping tranny. If the fluid levels are correct and you still get the slipping, then it more than likely indicates a tranny where the clutch packs are worn to the point of needing a rebuild. I was close to this point. My original 67 Powerglide would leave hard and pull, but shifting from low to high it would take some time. I went to the next level and ditched the PG and went to a TKO 600. I run 4.10's and wanted to be able to drive the car on the highway. The reason for going to the manual is I was bored of just puting it in gear and going. It sounds like it's time for either a new tranny or to rebuild this one. Find yourself a GOOD tranny shop. They have gauges they can hook to the input and output ports of the tranny and gauge what condition the tranny is in. Hope this helps.
 

·
Registered
Joined
·
76 Posts
Discussion Starter #3
Yeah, I filled up the tranny with fluid before I drove it. It seems to shift fine but once I'm in third (which is at around 30-40 mph thanks to 4.11 gears), and I need to accelerate faster than a grandma, I hit the gas and the RPMs increase but the car doesn't speed up.

I already got a 700r4 sitting in my garage (and the best tranny shop in town). I was planning on waiting until after I moved in to my new house to spend 2 grand beefing it up and swapping it in, but stuff happens...
 

·
Registered
Joined
·
1,394 Posts
Sounds like you cooked your trans with low fluid level. Quick, temporary fix; fill it with power steering fluid. It will swell the internal seals. ..... P.S. This solution might work for hours or years. Depends how bad it is and how hard you beat on it.
 

·
Registered
Joined
·
76 Posts
Discussion Starter #5
And run the transmission with the power steering fluid? Is this safe?

If it doesn't help, would it have been safer to just stick with transmission fluid? I mean, could it cause any problems?
 

·
Premium Member
Joined
·
3,403 Posts
What kind of car do you have, could it be a stopped up cat conv, bad exhaust system?
Could be trans, or other things?
 

·
Registered
Joined
·
76 Posts
Discussion Starter #7
It's a 68 Camaro. The transmission is a TH350 w/ shift kit. I have brand new Magnaflow exhaust behind brand new headers and no cats. I have a feeling it's the transmission. I'm going to go drive it today and see how it does if I get some wiring done, but I'm pretty sure I'm just going to have to put in the 700r4 sooner than I had hoped.
 

·
Registered
Joined
·
1,394 Posts
You are not running straight p/s fluid, just filling the trans. So it will be a mix of trans fluid and p/s fluid. Is it safe? Yes, it wont blow up or anything. Could it cause problems? Yes, but again, if the trans is cooked, which it sounds like it is, what do you have to lose? I got this whole thing from an article I read years ago which basically said that "Transmision overhaul in a can is basically just power steering fluid." I know it works because I put it in a slipping trans I had and it immediately worked better and lasted until I sold the car (months later). Feel free to get other opinions on the topic. Good luck.
 

·
Premium Member
Joined
·
3,123 Posts
When I had my TH350 in my 68, I had the exact same problem. I knew it was the tranny. Got to the point where I would only drive on side streets as anything over 40 mph would do what you just described. Then the reverse went out so I could not backup against any slope but would have just enough pull on level ground. I kept driving it just had to make sure I would never get myself in a position where I had to backup against a slope. Then one day the big D went out as in "Drive". I got a stage-3 700R4 now and it's all happiness again.
 

·
Registered
Joined
·
76 Posts
Discussion Starter #10
Ok, so I drove the car today and got a better feel for the symptoms.

I start out in first, and the engine seems to rev up much faster than the car is actually moving forward.

Then I shift into second and it shifts fast and jerks into gear (has a shift kit).

Again in second, the engine seems to spin up fast but not much increase in speed, and again I shift and it jerks into third.

Once I'm in third, I think it normally accelerated alright, but I wasn't really pushing it at all today... just nice smooth throttle adjustments.

So the actual shifts are tight... does this shed any new light or just reinforce what you guys already thought?
 

·
Registered
Joined
·
5,277 Posts
Could be a bad sprag in the torque convertor. The sprag holds the stator inside the convertor still under load but allows it to free wheel a bit when cruising. When the sprag fails, the stator won't redirect fluid in the torque convertor properly which will make it feel soft.
 

·
Super Moderator
Joined
·
32,347 Posts
I'm betting on a toasted trans. The higher the speed, the greater the load - air friction.
 

·
Registered
Joined
·
3,765 Posts
Like I said in my 1st reply, take it to a tranny shop. They have gauges they can hook to it and tell you if it's producing the correct pressures or not.
 

·
Registered
Joined
·
8,349 Posts
I had a 700R4 that did the same thing when the trans went out. An auto still has clutch packs in it and what you're seeing is slippage. It may be the pump but it doesn't take much driving one around with one bad part to take out all the rest. If it doesn't have a manual valvebody and won't upshift in drive, that's a sure sign. That's what mine did and it wouldn't accelerate in third, only rev.

When I had mine rebuilt, the pump they put in failed and it puked fluid out and wouldn't even move.
 

·
Registered
Joined
·
76 Posts
Discussion Starter #15
Alright, since this definately isn't looking like an easy fix, I finally decided to go for a 2004r (instead of the 700r4 I picked up). Going to get this in there asap rather than attempting to fix the th350. Thanks for the insight everyone, it cemented my decision to swap in a new trans instead of waiting.
 

·
Registered
Joined
·
5,277 Posts
Be sure to flush out your oil cooler lines. Otherwise any debri from the 700R4 will make it's way into the lubrication passages of your new tranny. I usually use an air hose to blow out what's in the lines and then run a little solvent through the cooler blowing out what's left with the air hose again. Probably have to repeat the process 2 or 3 times until you feel like you've got the crud out.
 

·
Registered
Joined
·
3,765 Posts
Alright, since this definately isn't looking like an easy fix, I finally decided to go for a 2004r (instead of the 700r4 I picked up). Going to get this in there asap rather than attempting to fix the th350. Thanks for the insight everyone, it cemented my decision to swap in a new trans instead of waiting.

If you're going through the trouble of swapping the tranny, why not go the extra bit and convert to a manual? I did and it was the best decision I could have ever made. No more puting it in gear and driving. How boring is that??? Muscle cars and sports car shouldn't even be offered with an automatic. I fall asleep driving an auto. It takes the muscle out of the "muscle car". At least for the street. Racing is different. Easier not to have to shift, but for the street, there shouldn't be an auto in a street muscle car, PERIOD!!!!!!!!!!!!
 

·
Registered
Joined
·
76 Posts
Discussion Starter #18
If you're going through the trouble of swapping the tranny, why not go the extra bit and convert to a manual? I did and it was the best decision I could have ever made. No more puting it in gear and driving. How boring is that??? Muscle cars and sports car shouldn't even be offered with an automatic. I fall asleep driving an auto. It takes the muscle out of the "muscle car". At least for the street. Racing is different. Easier not to have to shift, but for the street, there shouldn't be an auto in a street muscle car, PERIOD!!!!!!!!!!!!
My original plan was to swap in a TKO, but when I look at the long list of things I want to do to the car, and considering many expenses I have moving into a new house right now, I changed my mind. It would cost me at least twice as much to convert to a manual. I'm having a 2004r rebuilt and swapped in for much less than the cost of simply acquiring a TKO and related hardware.

I do agree with you though. Ever since I got my first motorcycle, I've loved having control over the entire vehicle, not letting it decide when to shift for me, etc. So I compromised with a ratchet shifter... it's not the real deal, but it will suffice. I can't feather the clutch or anything, but at east I can bang it into gear when I want and chirp the tires while doing it!

If I had plenty of cash (or time to wait and find parts for cheap), heck yeah I would be putting in a TKO. I don't have either right now and won't for another year until I get out of college and finish all my planned upgrades for the house, etc.
 

·
Registered
Joined
·
3,765 Posts
I know what it's like to not have the funds to do what you really want. I feel you on that. I have found that by comprimising on what I really want caused me to actually spend more money in the long run. All the time and money I put into the PG trying to get it run with the performance and drivability I wanted cost me damn near as much as it did to swap in the TKO. Just something to think about.
 

·
Registered
Joined
·
1,394 Posts
Be sure to flush out your oil cooler lines and radiator passageways. Otherwise any debri will make it's way into the lubrication passages of your new tranny and ruin it. ..... I know dnult said it earlier, but its worth repeating and the number 1 cause of replacement transmission failure. ......... BTW, do a little research on here re the swap to the 200 4r. I put one in my 69. Its not exactly a bolt in.
 
1 - 20 of 20 Posts
Top