Dual Range Hydro Problem...

[Deleted User]

I recently had my dual range hydromatic rebuilt. I have had problems with it since day one after I picked it up. When starting out from a stop, it quite often won't go into low unless I manually shift it into low. Also, sometimes it will idle rough while sitting at a light while in drive. If I then shift it into nuetral then it idles fine.



The guy who owns the trans shop is a college buddy of mine and he has the car again but I'd like to give him some ideas as to where to look for the problem. Anyone have any ideas? Thanks!

Ol racer

The Hydros are tough and were in everything from cars to Military Tanks but they have been out of production for many yrs so with all due respect to the Trans Shop they probably do not have any recent experiences on the Hydro or even a Manual anymore. If you do not get any other response, I suggest doing like I did and buy an old Hydro Service Manual (available from $10 up) on eBay to assist your Shop Mech. They have many helpful Trouble Shooting Tips to try before removal.....

[Deleted User]

nhp1127 wrote:

I recently had my dual range hydromatic rebuilt. I have had problems with it since day one after I picked it up. When starting out from a stop, it quite often won't go into low unless I manually shift it into low. Also, sometimes it will idle rough while sitting at a light while in drive. If I then shift it into nuetral then it idles fine.



The guy who owns the trans shop is a college buddy of mine and he has the car again but I'd like to give him some ideas as to where to look for the problem. Anyone have any ideas? Thanks!

Your trouble is in the valve body. One spring in the wrong place or they tightened the valve body to tight and it's making valves stick. The rough idle is it's in two gears, so I say valve body. Walt.

[Deleted User]

Ol racer wrote:

The Hydros are tough and were in everything from cars to Military Tanks but they have been out of production for many yrs so with all due respect to the Trans Shop they probably do not have any recent experiences on the Hydro or even a Manual anymore. If you do not get any other response, I suggest doing like I did and buy an old Hydro Service Manual (available from $10 up) on eBay to assist your Shop Mech. They have many helpful Trouble Shooting Tips to try before removal.....

Yup- you are correct in the inexperience. His Dad was an expert on them but he passed away a few years ago. His son used to help him out on some of them but he never did them fulltime with his father. I guess he'll have to learn...

bob ward

nhp1127 wrote:

Yup- you are correct in the inexperience. His Dad was an expert on them but he passed away a few years ago. His son used to help him out on some of them but he never did them fulltime with his father. I guess he'll have to learn...

I had my dual range Hydramatic rebuilt nearly 2 years ago. The guy I took it to runs a successful business rebuilding mainly the current crop of automatic boxes.



He was quite happy to tackle mine because he likes a challenge, he does 2 or 3 hydras a year. As he said, some people do crosswords and Sudoku, I rebuild old automatic gearboxes.



But he did tell me there are a million and one traps for the unwary when rebuilding a Hydramatic.



This is partly because most of the living knowledge has gone and also because there are so many subtle variations in internals for boxes for different vehicles and subtle variations caused by upgrades to the box over its life in a particular vehicle. Single range/dual range as one instance.



But the main point I was getting round to is that there does exist a strong Hydramatic internet support network. It is something my rebuilder spoke of and he said he uses it as an information source when he is not sure about something or has a problem to solve.

Unknown

I purchased a book from Faxon literature that deals with hydros from 1951 thru 1954, it is a compilation of Hudson factory manuals. It gives changes and notes to updates from year to year, valve body changes etc; worth more to me than I paid for it. I found it on Hudson E-Bay. It sounds like the 2-1 shift valve is stuck. Did your rebuilder use the special tool to allign the governor to the valve body? When I go thru a valve body it takes me at least 1 1/2 hours, all valves are removed, body is flat sanded on all surfaces,cleaned and all valves cleaned and lightly sanded with 320 paper if they move freely under their own weight. Good Luck Lou Cote :cool:

[Deleted User]

I wanted to give you guys an update on what the eventual problem was. My friend (yes he had a manual) said that they had torn a seal when they had originally put the tranny together. He wasn't specific on the exact piece that was messed up but I know they had to take the whole tranny apart again and start from scratch to find the problem. So, bottomline is that the car now drives and shifts like a dream.

It makes me happy that he did whatever was needed to be done inorder to make it right. That's why he is a friend of mine, good character, nice guy.