suddenly difficult shifts at lower gears (manual)

[cruiser54]

Now we're getting somewhere.

 

Do this: Pump the clutch pedal about 40 times and then walk away from it. 

See if it shifts better after that. 

[Eagle]

Couple of points:

 

You haven't said anything about how you shift, or what kind(s) of manual transmission vehicles you have driven in the past. Your expectations may not be aligned with reality.

 

The Comanche is a TRUCK. It's not a drag racer. If you're the type of driver who likes to bang their shifts as fast as the hand can humanly move the shift lever, you have the wrong vehicle and the wrong transmission. I have driven on the order of 350,000 miles in Jeeps with the BA 10/5 transmission. I also live in New England, so I know about cold weather behavior. With all the Jeep XJ/MJ manuals (BA 10/5, AX-15, and NP 3500/3550), you can't rush the shifts -- and for some reason that is especially true for the first-to-second shift. After pulling the lever out of first, it's generally necessary to hesitate for a half a heartbeat or so before shifting into second.

 

For the first-to-second shift, my experience is that RPM is critical. What I found is that you should get up to exactly 2250 RPM in first before shifting to second. Either that, or if you're pointing downhill you want to be just barely rolling. If you're going uphill -- don't even think about second gear when it's cold. Run the revs up high enough that you can skip second gear and go directly into third, or shift into second at the lowest possible RPM to be able to engage second without stalling the engine.

 

This is assuming that the clutch is properly disengaging. ALL the forward gears are synchronized. Reverse is not. If you can't shift it into reverse when the vehicle isn't moving and your foot is on the clutch pedal, the problem is the clutch, not the transmission or the transmission oil.

 

[brucecooner]

2 hours ago, Eagle said:

Couple of points:

 

You haven't said anything about how you shift, or what kind(s) of manual transmission vehicles you have driven in the past. Your expectations may not be aligned with reality.

 

The Comanche is a TRUCK. It's not a drag racer. If you're the type of driver who likes to bang their shifts as fast as the hand can humanly move the shift lever, you have the wrong vehicle and the wrong transmission. I have driven on the order of 350,000 miles in Jeeps with the BA 10/5 transmission. I also live in New England, so I know about cold weather behavior. With all the Jeep XJ/MJ manuals (BA 10/5, AX-15, and NP 3500/3550), you can't rush the shifts -- and for some reason that is especially true for the first-to-second shift. After pulling the lever out of first, it's generally necessary to hesitate for a half a heartbeat or so before shifting into second.

 

For the first-to-second shift, my experience is that RPM is critical. What I found is that you should get up to exactly 2250 RPM in first before shifting to second. Either that, or if you're pointing downhill you want to be just barely rolling. If you're going uphill -- don't even think about second gear when it's cold. Run the revs up high enough that you can skip second gear and go directly into third, or shirt into second at the lowest possible RPM to be able to engage second without stalling the engine.

 

This is assuming that the clutch is properly disengaging. ALL the forward gears are synchronized. Reverse is not. If you can't shift it into reverse when the vehicle isn't moving and your foot is on the clutch pedal, the problem is the clutch, not the transmission or the transmission oil.

Ah, no synchros on reverse, it's good to know the purpose of that test.

 

I do NOT shift quickly.  I don't do anything quickly. Just ask my boss.

Joking aside, I abhor the needless mistreatment of equipment, and I've driven my manual Ranger to over 230K without any issues.

 

I stopped on empty streets and shifted into reverse many times over a drive around the neighborhood today, and only one required cycling the clutch.

 

I had noticed in the Jeep the shifts are easier with that slight pause between 1st and 2nd. 

And it does seem to prefer being shifted above 2000 rpm.

 

Next step is to try cruiser's suggestion to pump the clutch a bunch.

 

It really is like I noted though, this is a new behavior. 

It had been shifting remarkably smoothly since I got it, then all of a sudden they got crunchy.

Crunchy, but not impossible, like when the clutch went out.

When the clutch went there was a hard wall between all the shifts.

 

 

[cruiser54]

Pump the pedal. 

 

BTW, Eagle is absolutely spot on regarding the BA-10s behavior. 

[pizzaman09]

If there is one thing I've learned about driving manual transmission vehicles, the older it is, the more you have to learn the character of each gear.  Ford Model A truck, have to double clutch everything and be light handed with the shift lever just suggesting it go into the gate to engage smoothly.  Austin Healey Sprite, always shift into second before engaging first, and a long pause between 3rd and 4th prevents grinding.  Jeep Comanche with the AX-15, slow shift into second from first, particularly appreciates a good rev match.  99 BMW M3, easy to shift but needs to be warmed up to make finding gears easy.  New Ford Bronco, so easy to shift it almost has zero feeling.  I can definitely say the BA10/5 was the smoother shifting transmission compared to the AX15 but only when warm.  When cold the BA10/5 really doesn't like to wake up.

[brucecooner]

Took it out again today.

A piece of advice I got years ago and have always used is to hold and move the shift knob like it's an egg you don't want to break.

 

Eagle's suggestion of shifting at 2250 and a slight pause from 1st to 2nd helped a lot.  It was still clunky, but better, and got better as the tranny warmed.

All the other gears were fine, I could ease it through most of the upper shifts with two fingertips and light pressure on the stick.

 

I'm still not above replacing the transmission fluid, but want to re-oil the other geartrain components first.

 

At this point I'll chalk this up to quality French automotive engineering, and just keep an eye on it.

[cruiser54]

Did you pump the pedal?

[ghetdjc320]

I’ll throw this out there for what it’s worth. I also have a great a many miles on the BA10, AX15 and NSG370. None of them are really truck trannys. The old 3 on the tree trannys and sm465’s were “truck” trannys. The BA10 was designed for a car and is a light duty but smooth shifting piece of junk. The AX15 saw life as the R151 behind turbo sports car application. All I’m saying is, don’t chock up bad shifts to a “truck” transmission. I’ve had problems with them all but they also shifted very well and didn’t require some special finessed technique to go in gear. The issues you are having do not sound normal. If I may make a suggestion; put aside the fluid or “truck” tranny debate for a bit and focus on that clutch. Try what cruiser said. We need to know if the clutch is fully disengaging before any more theories can be advanced. 

[cruiser54]

Yes!! Also, did this start with the clutch replacement? 

[brucecooner]

5 hours ago, cruiser54 said:

Yes!! Also, did this start with the clutch replacement? 

Sorry, I didn't answer your questions.

 

Yes, I DID pump the clutch a bunch before heading out, that's definitely a variable to consider.

I've checked and the clutch fluid reservoir still shows plenty of fluid, but I know that doesn't mean everything's working down below.

 

I've been driving on the new clutch for a few months, but I have not put a lot of miles on the truck in that time.

So these grindy shifts only started recently, but mileage wise the clutch isn't that old, so maybe there is something there.

What's confusing is that the problems seem isolated to 2nd, mostly.

The other gears are very smooth, BUT, maybe I'm just better at rev matching the upper gears.

 

I've heard the BA10 is light duty to begin with, and this one is pushing 200K, and I'm pretty sure this truck towed in a previous life.

Since I got the truck I've been wondering if there are any good transmission swaps, but I'd guess choices are very limited.

And I'm not looking to go rock crawling, just the occasional washboarded dirt or rocky mountain road, and the BA might be plenty for that (long as the clutch is working).

 

How hard is a clutch bleed on these? 

[cruiser54]

A bleed is a b*@ch. 

With the clutch working as it does, the pumping shoulda made a difference if it were an air issue. 

 

So, when clutch was first replaced, you didn't have this issue?

It just cropped up afterwards? 

[brucecooner]

6 hours ago, cruiser54 said:

A bleed is a b*@ch. 

With the clutch working as it does, the pumping shoulda made a difference if it were an air issue. 

 

So, when clutch was first replaced, you didn't have this issue?

It just cropped up afterwards? 

Yep.  Started all of a sudden past couple of weeks. 

The pumping test I did the other day didn't make much difference.

This behavior did coincide with cooler weather, maybe like me the BA doesn't like the cold.

 

I took it out today, my destination was about 20 miles away.

On the way out of my neighborhood it had the usual difficult shifts but on the way back, warmed up, it did just fine.

Schizophrenic little devils, these transmissions.

[Agreen]

Look at your pedals.  Does your clutch pedal look lower than the brake pedal?

 

I had the same issue on mine.  When I got it the clutch pedal was frozen.  I, being the brute I am, stomped it.  It freed up, I got it running (after sitting for several years) and drove it.  Getting into gear was a normally a problem, so I had to double clutch every time I shifted.  I figured the master and slave cylinders needed replacing.  Commence 3 days of bleeding.  2 pints of brake fluid were used and I still never "got all the air out".

 

The little tab on the clutch pedal likes to bend sometimes.  

[cruiser54]

Perform the pedal pump again just for fun. 

[brucecooner]

8 hours ago, cruiser54 said:

Perform the pedal pump again just for fun. 

 

You have a weird definition of fun.

 

But I have a name for this truck now.

 

"Heartbreaker."

[cruiser54]

Pump that pedal again. For the sake of science.....

[brucecooner]

For science!

 

Got behind the wheel and pumped the clutch about 50 times.

Took it out for a spin around the neighborhood.

It was only 2nd giving me trouble this time.

3rd has been problematic lately, but not after all that pumping.

 

Our neighborhood streets are covered with speed dips (think shallow little drainage ditches) so there was a LOT of slow rolling shifts into 2nd coming out of the dips, lots of chances to test 2nd.

 

I mixed up the routine this time, by taking it out of gear and pumping the clutch as it coasted.

If I timed it juuuust right, so I went into 2nd right on the last pump (disengage), the shift into 2nd was usually easier.

By the end of the drive the tranny was warm and it was shifting pretty easily all through the range.

 

I did lots of shifting into reverse too, and they all went right in (this is after all that pumping, remember).

 

I can also say the clutch feels spongier than it used to.

 

AND, there's other news to report.

I noticed a new dark spot under it yesterday, climbed under there and found fluid on the bottom of the bell housing, again.

 

This fluid is distinctly lighter than the oil seeping from the drain plug (I was a dork and didn't put a washer on the plug), so I'll be danged but it looks like I might be back at square one with this clutch.

 

I'm wondering if 2nd gear, as the most problematic of the bunch, or maybe with the most tired synchros, is serving as a canary in the coal mine for the clutch overall.

 

So I'll be contacting the shop soon.

 

I really enjoyed the drive though, even with the shift shenanigans. 

While cruising I debated naming the truck "schizo", which would easily fit on a license plate.

[Eagle]

I think you are discovering that the BA 10/5 doesn't like to shift into second gear when cold. It's the nature of the beast.

 

You mentioned rev matching, which prompts me to comment that when I learned to drive (back in the days of "three on the tree" manual transmissions), my grandfather taught me to double clutch.  Back then, I was good enough at it that I could shift into non-synchronized first gear at up to 15 MPH with no gear clashing. I have always double-clutched my downshifts on the BA 10/5, and I also do so in my 2000 XJ 5-speed. It's technically not necessary, but I think it helps the synchronizer rings to live longer.

 

But with the BA 10/5, in colder weather second gear is problematic even on upshifts, You either shift at exactly 2250 RPM, or you "granny" shift it when you're just barely even rolling -- and that doesn't work if you're heading uphill.

 

[brucecooner]

13 hours ago, Eagle said:

I think you are discovering that the BA 10/5 doesn't like to shift into second gear when cold. It's the nature of the beast.

 

You mentioned rev matching, which prompts me to comment that when I learned to drive (back in the days of "three on the tree" manual transmissions), my grandfather taught me to double clutch.  Back then, I was good enough at it that I could shift into non-synchronized first gear at up to 15 MPH with no gear clashing. I have always double-clutched my downshifts on the BA 10/5, and I also do so in my 2000 XJ 5-speed. It's technically not necessary, but I think it helps the synchronizer rings to live longer.

 

But with the BA 10/5, in colder weather second gear is problematic even on upshifts, You either shift at exactly 2250 RPM, or you "granny" shift it when you're just barely even rolling -- and that doesn't work if you're heading uphill.

 

I drove it a bit today, and it behaved exactly as you described.

When I started, all the gears except 2nd were friendly. 

After it got warm, 2nd joined the group and played nicely.

 

There is a small amount of fluid where the original clutch leak showed up, but that could be oil getting blown back from the small drain plug seep, so just keeping an eye on it for now.   Long as it's just 2nd acting up though, going to turn up the radio and not worry about it.

 

[ghetdjc320]

On 11/12/2022 at 11:14 PM, brucecooner said:

suddenly the transmission (BA10/5) realllly doesn't like going out of 1st and up to 2nd.

^^ This is what i still see as the problem. You did not have this issue earlier. You need to find the root cause of this change. What eagle is describing is what he sees as characteristic of this transmission not the sudden onset of a problem. Personally I have never had any issues shifting into second or any other gear with the ba10/5. But putting all that aside, any sort of “sudden” onset of a problem is likely to have a root cause. Chocking up a sudden onset problem to something that you’ve been told is a problem you should be having is going to invite further issues. You’ve identified a leak of hydraulic fluid at the bellhousing. You’ve also stated that it’s not shifting as smoothly overall as when you got it. You recently had clutch work as well as a fluid change. You could first of all verify that there is indeed plenty of tranny oil in it by opening the fill plug and checking. A leaking slave cylinder or loose hydraulic fitting will only get worse. Keep hunting down the issue. I suspect you will indeed find the problem one way or another.