News:

Due to a technical issue, some recently uploaded pictures have been lost. We are investigating why this happened but the issue has been resolved so that future uploads should be safe.  You can also Modify your post (MORE...) and re-upload the pictures in your post.

Main Menu

Intermittent Jetaway problem, failing to engage top gear when really hot.

Started by kittykatjaz, December 15, 2008, 03:07:03 AM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

kittykatjaz

Hello,

My 61 Deville has an intermittent problem with the Jetaway transmission where it sometimes does not want to go into top gear when really hot. It is not all the time but when it does occur it is normally after freeway driving on a hot day. Below is a bit of an explanation of what happens.

When cold, all gears shift perfectly. When it warms to normal operating temperature the 2-3 shift becomes a little stronger and less smooth though still acceptable and 1-2, 3-4 shifts are perfectly smooth. When the transmission is hot from either freeway driving or a hot day and travelling a distance. If I was to stop at the traffic lights for a short time then take off the transmission fails to engage top gear. On light power or acceleration it stays in third but if I roll off the throttle into deceleration then it feels like it is going to or just slips into top gear, that’s until I apply the power then it cruises along back in third. Then if I was to stop again and idle in drive for a few minutes or more the transmission with then behave normally again.

When I put it on the road about five months ago from which it had been off for 12 years. The transmission was noisy at high revs and it developed problems with selecting second and top round town. So I drained all the fluid, pulled the pan and valve body, stripped and cleaned it all then re-assembled.  This corrected the noise, improved the shifting substantially and fixed the problem with second gear and seemed to fix top gear until a recent trip down the freeway.

So this problem seems to act like a sticky valve or governor but can anyone with a bit of Jetaway experience tell me if this is common and point me to a more precise area before I start pulling it apart again?

I have quite a bit of experience with rebuilding Turbo Hydromatics and Borg Warners from Jaguars so this is not a daunting task but I do not want to waste time if someone can point me in the right direction.

Regards,

Jaz

Roger Zimmermann

I have the impression that you are good for a rebuild...Your problem may come from the front unit coupling. There is probably a tiny leak in that coupling; while cold or just warm, the leak is not large enough and you notice nothing. However, when the oil is hot and thin, the leak is sufficient and the front unit coupling cannot work properly.
For 2 years, I restored a '59 transmission (which is almost identical to yours); I did not check with compressed air if the front unit coupling was working properly. At cold, no problem. When the transmission was warm, no second and no 4th gear. Reason: the cover in aluminum was disformed and one of both seals was ineffective. A new cover solved the problem.
Somebody else in Italy had the same problem. Recently, he sent me his front unit coupling: the cover was badly damaged, probably by  driving abuse.
Another case on a '57 Brougham, years ago: very intermittently, no 4th gear. After removing the front unit coupling, we discovered that the cover was cracked because the procedure to remove it from the case was incorrect. A new cover solved the problem.
In your case, the rubber seals on the cover may have deteriorate during the storage and they are leaking.
I would gladly restore your transmission; however, you have to bring the transmission to my shop. Small detail: I'm located in Switzerland, which will not be very practical for you.

Good luck!

Roger
1956 Sedan de Ville (sold)
1956 Eldorado Biarritz
1957 Eldorado Brougham (sold)
1972 Coupe de Ville
2011 DTS
CLCMRC benefactor #101

Roger H

Can you check any pressures? Does that tranny have a main line pressure port you can hang a guage on? or a high gear port?
you may be able to rig up some guages you can see while driving to narrow down the possibilities.  (Does the main pressure remain high when It won't shift?)
Roger Hundtoft
1936 Fleetwood 8509
Lynnwood Wa

kittykatjaz

Hi Guys,

The front coupling could be a cause but I have some doubts as second gear works fine when the the top gear problem starts to play up. Plus it is an intermittent problem where after a few minutes of idling the transmission will behave itself again and the top gear will not play up for the rest of the drive. That's what makes me think it could be a sticky valve. A pressure gauge would be very beneficial as pressure is what it feels like, but I left the auto industry as a mechanic in the mid 90's so do not have access to many specialised tools any more. Maybe someone hires them.

If the transmission needs to be rebuilt that is something I will do myself. It would be a bit of fun to see the insides of one of these   :)

One last thing, this car had been of the road a long time, maybe it just needs some really good long runs to get everything working well again, normally its just cruising around town where it runs perfectly.

Jaz

Stampie

Mine did the same until someone made me look stupid and pointed out that I had the wrong radiator cap in it.  Replaced with the right one and now she never gets hot enough to cause the problem.

Stampie
If... the machine of government... is of such a nature that it requires you to be the agent of injustice to another, then, I say, break the law.  ~Henry David Thoreau, On the Duty of Civil Disobediance, 1849

If we desire respect for the law, we must first make the law respectable.  ~Louis D. Brandeis

kittykatjaz

Hi Stampie,

The engine runs pretty cool. The temp gauge on a hot day barely nudges over the first quarter. Plus the transmission has an external cooler fitted and does not use the radiator cooler.

Thanks though for your idea!

Jaz

Walter Youshock

Is the external cooler an add-on?  1957 was the last year the trans cooler was actually mounted on the trans.  It was fed by 2 hoses that ran off the water pump, under the intake and down to the cooler.  1958 came out with the trans cooler on the lower radiator tank with metal lines running to the trans.
CLC #11959 (Life)
1957 Coupe deVille
1991 Brougham

kittykatjaz

The external cooler is an add-on. It is one of those air cooled units which are normally fitted in front of the radiator. It has the cooler pipes running straight into it and back to the transmission bypassing the radiator trans cooler.

This car of mine is no concourse winner and has had a lot of "uh-ha" repairs over the years. Probably as I am based in Australia and some of the previous owners/mechanics were too lazy to track the correct parts and did substandard repairs with local parts poorly modified to fit. It has been a slow and expensive job going through and fixing these problems.

Jaz

Walter Youshock

Well, mechanically, that shouldn't be considered a bad thing.  Those old systems weren't the best, so maybe these mods helped along the way.  On a daily driver, it had to get around.  Now, it is "retired" and a car of leisure.

Exactly what are your intentions with the car--return to original; get it back on the road?  It made it this far...

If the trans is gone, I'd rebuild it and take it back to original.  If you are forced to invest the $$$, the best investment is making it "new".  They did work then.
CLC #11959 (Life)
1957 Coupe deVille
1991 Brougham

kittykatjaz

Hi Walter,

My intentions with car is to have a nice driver which is basically standard with a few reversible mods like alternator, radio etc, but nothing that requires permanent modification. Which it is pretty close to now. To bring it to an original show stopping condition would take far more resources than I have. Though it has little rust the main structure of the car not good enough to restore to factory cond without spending an absolute fortune on it.

The transmission works perfectly round town and only becomes apparent occasionally after a long drive at speed down the freeway which is not often. So until this problem develops into a more common thing it will stay in the car. Once it gets worse then I will completely rebuild it.

Jaz

Roger Zimmermann

In 4th gear, the front unit coupling is full, the neutral clutch is on and the rear clutch is on. Either dirt in the valve body or a low oil pressure may cause your problem. I would also have a look at the external oil cooler; who knows if he's working properly?
Roger
1956 Sedan de Ville (sold)
1956 Eldorado Biarritz
1957 Eldorado Brougham (sold)
1972 Coupe de Ville
2011 DTS
CLCMRC benefactor #101

Ohio57-62Sedan

Just my thought's on this I would try to find an additive called LUBE GUARD.... ((red bottle only)) I hope you can get it down there. Napa has it here.. It works really good on the valve bodys and good for the clutches too.. I wouldn't use anything else in any transmission..  ;)


Otto Skorzeny

I would drain the fluid and check the filter before adding the LubeGuard. As mentioned before, check the transmission cooler and all the lines. Since you said this only occurs when the transmission gets really hot, I wonder if the cooler is not working as it should. Maybe it's got some crud in there. Fill everything back up with the correct fluid and add the Lube Guard.
fward

Ask not what your country can do for you, but what you can do for YOURSELF

HUGE VENDOR LIST CLICK HERE