Sluggish transmission, performance?

[Scoopy G]

Hello again friends,

My 67 Newport is doing great, the newly re-upholstered seat is awesome, and my ElMarko re-dyed carpet looks great. But there are some lingering problems.....

TRANSMISSION: The tranny is very sluggish when I first start the car up. I let the engine warm up, then put it into reverse, or drive, and the response is very sluggish. It's as if the brakes are sticking, which they are not. Once the car is on the highway, everything is just fine, it shifts good and runs at 80mph with no problems. It's like me, slow to get going. Any suggestions?

ENGINE: It starts nice and runs well, but it ain't got no punch. It will cruise at 80, but there just isn't any power at the pedal. Accelerator pump's bad maybe? Linkage is not adjusted right? It will throttle up just fine, but under load it's a dog, and I gotta think it isn't the engine's fault, there must be something out of adjustment. Hoping you guys will know what's wrong.

Otherwise I am loving me some Chrysler. I wish I had come to the party years ago (though I did have several Darts I liked very much). With the Newport and the 63 Riv, I am in Detroit 60s Heaven.

 

[Davea Lux]

The front pump on the transmission is disengaged when the transmission is in park. If the car sits for days between uses, the oil in the torque convertor drains out. Then when the car is placed in gear, it will take a short time to refill the convertor so that the car will move. That much is normal. You may also have a transmission filter that is partially clogged if the transmission is sluggish all the time. I would suggest removing the transmission pan and replacing the filter and a band adjustment should be done at this time also. Torque convertor should be drained and the transmission filled with clean fluid.

You have not really given enough information to address the sluggish engine performance. If the engine runs smoothly, there probably is not a misfire. Have you checked the timing? That would be where you should start, be sure the timing is set to the factory specs. Next, check the vacuum advance hose to the distributor and be sure it is not disconnected or leaking. Get a clean length of vac hose and hook it to the vacuum advance canister on the distributor, blow into it lightly, does it hold pressure? If it holds pressure, the unit is probably ok. Be sure that the vac advance is hooked to throttle plate vacuum and reattach it. If the accelerator pump is bad, the engine will start to die when you punch the throttle, sometimes it will also fart back thru the carb. If that is the case, you are probably headed for a carb rebuild. Try checking these things and report back. You can get a free download of the FSM at www.mymopar.com, you will find it in the Tools/Reference section. The service manual has the factory specs for timing etc.

Dave

 

[Scoopy G]

Thanks Dave, your information is most helpful. I'll check the tranny items you mention.

I set the engine timing to spec, and all vacuum hoses were replaced, so I've no reason to suspect a vacuum leak. No misfires, as all cylinders are firing OK, and the car idles smoothly. I did install a Pertronix kit in the distributor, so I'm not sure if the vacuum advance would play a part with the Pertronix kit. Again, the engine starts fine, it idles fine, and it cruises fine. The only thing it doesn't do well is kick in when I mash on the accelerator pedal. And it doesn't kickdown shift either which may not be related to the carb, other than the kickdown linkage.

 

[Davea Lux]

Thanks Dave, your information is most helpful. I'll check the tranny items you mention.

I set the engine timing to spec, and all vacuum hoses were replaced, so I've no reason to suspect a vacuum leak. No misfires, as all cylinders are firing OK, and the car idles smoothly. I did install a Pertronix kit in the distributor, so I'm not sure if the vacuum advance would play a part with the Pertronix kit. Again, the engine starts fine, it idles fine, and it cruises fine. The only thing it doesn't do well is kick in when I mash on the accelerator pedal. And it doesn't kickdown shift either which may not be related to the carb, other than the kickdown linkage.

You should check the information that came with the Pertronix unit. If you bought one the complete units with the distributor, Most of them have an adjustable vacuum advance and the instructions should show you how to adjust it. If you bought the under cap unit that uses the existing distributor, this will not be an issue. Which engine is this, which carb and how many miles are on the engine? The FSM gives details on how to adjust the kick down linkage.

Dave

 

[Scoopy G]

Thanks again Dave. Pertronix kit is the under cap unit. Engine is 383 with 2-barrel. Engine has 85K miles.

 

[Davea Lux]

Nice car. Did the car used to have better performance? The reason I ask is because the 2BBL versions of the 383 were entry level engines that were not noted for a high degree of performance. That 383 2BBL was a grocery getter. If you get the kick down properly adjusted, it should perform a lot better.

Dave

 

[rkrochen]

Definitely need to adjust the kickdown it’s critical to performance and tranny life.

It’s not uncommon for the tranny to be sluggish after sitting for awhile. Mine has done so since I got it. I changed the fluid, filter and adjusted the bands. What I do is start the car up and let it run for a couple of minutes. Then I put it in drive for and sit there for a short time before I back it out of the garage. After that it’s fine. As mentioned above it is the oil draining out of the pump, not a big deal.

 

[garyh]

I start my Mopars in Neutral if they sit more than a day or two. That fills the convertor.

 

[LocuMob]

Definitely need to adjust the kickdown it’s critical to performance and tranny life.

This.

 

[Ross Wooldridge]

I start my Mopars in Neutral if they sit more than a day or two. That fills the convertor.

Drain back is common. To avoid wearinhg out the reverse or forward bands waiting for the converter to fill while IN GEAR, run the car in neutral, which runs the trans pump.

Don't wait for the pump to fill it in gear, or drive it that way.

A poorly adjusted or non-functioning kickdown will also damage your trans.

Make sure it is adjusted as per the FSM, and that the trans linkage return spring at the carb is there and of the correct tension.

 

[67Monaco]

Drain back is common. To avoid wearinhg out the reverse or forward bands waiting for the converter to fill while IN GEAR, run the car in neutral, which runs the trans pump.

Don't wait for the pump to fill it in gear, or drive it that way.

A poorly adjusted or non-functioning kickdown will also damage your trans.

Make sure it is adjusted as per the FSM, and that the trans linkage return spring at the carb is there and of the correct tension.

I normally start the car in neutral just for that purpose. Even just cranking helps fill that converter again.

 

[detmatt]

I always put the car in neutral after I’ve started it and it’s warming up a bit.

 

[CBODY67]

When our '66 was newer and still had the factory-fill ATF in it, it had a bit of slowness to move when put into "R" on first cold start-up. Our '69 Chevy pickup (THM400) didn't do that, by comparison. After the first ATF change, at the dealer with Chrysler fluid, it got worse. I later read that Chrysler's factory-fill ATF, back then, was a multi-vis fluid to help with that issue. On a hot restart, no problems at all, hot or cold weather. BUT the "easy fix" was to just start the car in "N" when cold or let it run a minute in "P" before putting the trans in "R", so the torque converter would fill quicker with the cold fluid. By about '70, the newer models seemed to be a little better in the cold start issues, by observation.

UNLESS somebody's been messing with the kickdown adjustment, how'd it get out of adjustment?

Power issues? With an add-on Pertronix? To me, that should not be the issue if it's just an "under the cap" add-on. Unless the spark is weaker or something like that. Spec timing should not be changed, nor should have been the vacuum advance. If the vacuum advance is bad, the performance will not be that much difference, BUT fuel economy will, like about 11mpg no matter what, even on highway cruise conditions. The normal mechanical advance will be all that happens, so WOT power would not be affected.

Check for a restricted muffler or something like that. Those things can happen gradually so no big, sudden difference is apparent, typically.

For good measure, you might get an ATF "cleaning/conditioning" additive to put in the trans. Then run it for a while (probably 100 miles?) and then change the fluid and filter. Back then, people used to put a can of Berryman's B-12 in the atf and drive the car a day or so. Turned the fluid black from the accumulated varnish. Then do a full change, maybe even two back-to-back changes, and things worked good again.

The car probably hasn't seen enough miles/use for wear on the valve body shuttle valves to have a wear issue in their bores, I'm guessing. But that would be something to consider if a full rebuild is done, NOT before. I'm suspecting everything internally is in pretty decent shape, anyway.

So, worry about the transmission performance FIRST, if nobody's been messing with the trans kickdown linkage, then it's probably good, I suspect. BUT the base adjustment (FSM) is to put the car at hot base idle, then remove the long, skinny spring that holds it all together, gently slide the linkage off of the pin, extend the lihkage fully forward,and the rear of the slot in the linkage should be at about 1/2 the diameter of the "pin" on the carb linkage, which should be the specified 2 turns pre-load the factory adjustment is. If that is where it is, then put it all back together like it came apart. If not, then adjust the slotted end such that the rear of the slot just slides onto the pin, then add 2 full turns pre-load into the linkage at the slotted end threads. Then reassemble as it came apart. For verification, download a similar model year FSM file at www.mymopar.com .

Keep us posted,
CBODY67

 

[Scoopy G]

Thanks everyone for the input. I will work on it and report back.

 

[mrfury68]

I always put the car in neutral after I’ve started it and it’s warming up a bit.

I have been doing this for years. It is just the nature of the beast. Beautiful car BTW.

 

[70bigblockdodge]

Adjust your timing and kickdown linkage. Fill converter on start up as mentioned above. I would adjust timing for maximum vacuum, make sure Vacuum advance is working.

 

[Davea Lux]

If the kick down linkage appears to be properly adjusted and you are still not getting a proper down shift, that can also be a symptom of a clogged transmission filter. A partially clogged filter results in decreased fluid flow and lower operating oil pressure to the servos and clutch packs. This in turn can cause sluggish performance, slippage and erratic up or down shifts.

FY! an engine with 85k should also have the timing chain checked for excessive slack. If the chain gets loose enough, it can jump a tooth resulting in very poor performance.

Dave

 

[Scoopy G]

Thanks Dave,

The car runs and idles very well, and it will cruise just fine at 80mph, so I doubt the timing chain is off. Since the car was a "street find" that was basically dormant for a couple of years, I suspect 2 things: one is that the carb probably needs rebuilt, and two, the tranny needs some service. I need to check the kickdown linkage, but even that isn't the problem...the engine just doesn't have any punch...and I realize it isn't gonna make that big-*** C-body drive like a Corvette, but compared to my '63 Riv it ain't got any guts...yet.

Many thanks again to all you guys for your advice and interest in my car. I'll keep you posted.

Rich in Tampa

 

[CBODY67]

Just what are you calling "punch"? Compared to a 401 Buick, the 383 will not have the same amount of low-end torque that Buicks are somewhat famous for. Consider, too, that your Riv probably has a 3.31 rear axle ratio, where the Newport should be a 2.76, PLUS a somewhat "tight" torque converter (typical of the '60s TF transmissions). And, of course, the Newport has a 2bbl carb and the Riv should have a 4bbl. So, not a good comparison, to me.

To me, the factory WOT upshifts on the '66 Newport were a bit low for best performance. 37mph for 1-2, for example. And about 75mph for 2-3, although in "2", it'll run up to 88mph in 2nd. Additionally, there is no part-throttle downshift on TF until the '71 model year, so it'll take WOT to get any downshift from 3-2, 2-1, or 3-1, unless you do it manually (i.e., 3-2). This puts all acceleration "on the converter" rather than "through the gears". What I did, after consulting with the old-line Chrysler service manager at the local dealership, was to add 2 additional turns to the kickdown linkage pre-load (which he had also done on his personal '67 Newport 383 2bbl). What that did was to hold the part-throttle upshifts a few mph longer for more acceleration with less throttle input, from a red light stop. The car felt much better to drive, that way, too! NO durability of other problems, either. I did similar with my ;67 Newport 383 4bbl, my '70 Monaco 383 4bbl, my '80 Newport 360 2bbl, with NO problems on any of them.

What this did was to put the min-throttle 2-3 upshift such that after the shift, the engine rpm was about 1000rpm, which seemed to work well there, too. Kept the converter more "locked-up" as a result, which should also keep the trans fluid temp down a few degrees, too, with less converter slippage (fluid slippage on the normal non-clutch-lock-up torque converter). But do that later after the other issues are fully investigated, determined, and fixed.

After I did the prior post, I later realized that what I described as the correct kickdown linkage adjustment was not quite as it should have been. I've edited the last paragraph to what it should be.

Take care,
CBODY67

 

[CBODY67]

One other thought . . . on the timing chain. IF the chain has never been changed, I'd not worry about checking it, just CHANGE IT instead. Back then, about 80K was getting into "questionable" territory for the factory timing chains, whether Chrysler or not. For a bit more money, you can upgrade to something like a Cloyes Plus-Roller chain or possibly the Mopar Perf roller chain timing set. These will be GOOD insurance for well past 100K miles more driving. The Cloyes Plus-Roller I put in my '77 Camaro had well past 400K on the chain, when we pulled the motor and put a 355 in its place. Just be sure to coat ALL sprocket surfaces and the chain in moly paste cam assembly lube and pour some GM EOS over the chain before you put the timing cover back on. The chain only gets "splash" lube, so some start-up lube will help things along.

Enjoy!
CBODY67