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Anyone familiar with the Funk 4000 Long Drop Transmission?

joestewart

joestewart

Well-Known Member
Joined
Oct 14, 2009
Messages
204
Location
Lafayette, LA
This is the transmission in my Lull 644. Ever since I've been driving this telehandler (about a year), it has always felt like the transmission clutches are slipping, so I hooked up a pressure gauge and measured the "charge pump pressure". According to my manual, this pressure should be 245-255 psi at 2000 rpm. The charge pump pressure that I'm measuring on my Lull is 190 psi (cold), and I assume its only going to decrease as the fluid temperature increases. The manual and the troubleshooting chart do not mention what to do if the charge pump pressure is low.

I have not measured the "clutch pressure" or "converter pressure" yet.

I drained and replaced the fluid about a year ago, and there was no metal / clutch material in the drained oil. The fluid smells ok now and the color seems fine.

Anyone familiar with this tranny? Or can anyone direct me to a good source of info / advice? How can I increase the "charge pump pressure"? Thanks
 
icestationzebra

icestationzebra

Senior Member
Joined
Jun 21, 2009
Messages
366
Location
WI
I am not familiar with this transmission so these are only suggestions, but if the charge pump pressure is low I can only think of a couple of problems.
- low oil (I assume you already checked this)
- worn pump (if true the charge pressure should increase as the engine rpm is increased)
- partially plugged inlet screen, if so equipped (if this is true the charge pressure may get worse as the engine rpm is increased)
- The only other possibilities I can think of would be a faulty pressure regulator/modulator or sticking dump valve, if so equipped.

I know this isn't a lot of help, but maybe it helps?

ISZ
 
joestewart

joestewart

Well-Known Member
Joined
Oct 14, 2009
Messages
204
Location
Lafayette, LA
Thanks ISZ!

First thing I'm going to study is transmission fluid level - I've checked it fifty times, but I have trouble reading it because fluid seems to wick up the sides of the dipstick, and maybe I'm over reading it (interpreting it as full when its actually low)

Gonna measure some clutch pressures today, according to the algorithm given in the manual.

Attention everyone who owns a machine with the Funk 4000 transmission: I have the service manual on pdf! Approximately 120 pages. I can email it to whomever needs it.

Title: Assembly and Disassembly Funk 4000 Series Shift-o-matic Transmission

I was looking at the photos in this manual - the internals of this transmission remind me of the Ford C6 - the clutches, pistons and valve body appear similar. Except for its mass and weight and bulkiness, the rebuild probably would not be too painful.
 
joestewart

joestewart

Well-Known Member
Joined
Oct 14, 2009
Messages
204
Location
Lafayette, LA
OK, I examined my machine today.

The transmission fluid actually appears to be overfilled. Its frustrating trying to read this dipstick though. I think its overfilled, but I don't think that the overfilling is the problem.

The clutch pressures in this transmission should be 240-255psi at 2000 rpm in each speed. I'm measuring 240psi in all gears EXCEPT low forward and low reverse. The clutch pressure of low forward is only 100psi. The clutch pressure of low reverse is also only 100psi. Not sure whats wrong here. I'll have to do some research.

I measured the converter charge pressure at 50psi - this pressure appears to be within specification.

This is weird because this tranny seems like its slipping in ALL GEARS, but it never heats up and the tranny fluid smells and looks fine. The only gears I use are low forward and low reverse. Granted, this forklift is only used about one day per month. Would love to get this tranny set right though.
 
T

trainpilot

Member
Joined
Sep 27, 2013
Messages
6
Location
Ukiah, CA
Occupation
R & D engineering
Hope you got your machine running properly. We recently purchased a little Grove carry deck crane with a Perkins 4 and a 4000 series Funk. I upgraded the engine and I think after replacing the torque converter seal and adding an electric power steering pump I'll be back in business. I'll take you up on your offer of the Funk manual if it's still good. john@flightrail.com thanks.
 
T

trainpilot

Member
Joined
Sep 27, 2013
Messages
6
Location
Ukiah, CA
Occupation
R & D engineering
A thousand thanks for sending the information on the Funk Trans. We were not able to obtain a manual when we purchased our crane. Without your help I wouldn't have known what kind of fluid to put in the trans, much less how to service and test it should that be necessary. Ours has a sight gauge on the side of the case--something I didn't discover until after the third round of pressure washing (The engine and trans are really buried inside the machine). Fortunately there is also a dipstick/filler tube at the top. I was pleased to find out that John Deere bought Funk and is still producing these units.
 
P

partsandservice

Senior Member
Joined
Feb 14, 2011
Messages
846
Location
Georgia
I not familiar with the 4000 funk but likely forward low and reverse low share a common clutch, low clutch. Trans pressure is not regulated individually for each clutch. So, low pressure when in those gears most likely means oil is dumping on the low gear shaft seal rings or the low gear clutch piston seal(s) are leaking.
 
Last edited:
joestewart

joestewart

Well-Known Member
Joined
Oct 14, 2009
Messages
204
Location
Lafayette, LA
partsandservice said:
I not familiar with the 4000 funk but likely forward low and reverse low share a common clutch, low clutch. Trans pressure is not regulated individually for each clutch. So, low pressure when in those gears most likely means oil is dumping on the low gear shaft seal rings or the low gear clutch piston seal(s) are leaking.
Click to expand...

Thank you for that. Will help when I get around to dropping this transmission and rebuilding it.
 
O

okbowhuntr

New Member
Joined
Apr 19, 2014
Messages
2
Location
OK
Joe, Could you please email me a copy of the manual? okbowhuntrwc@gmail.com , my old email has been cancelled.
Also, would you happen to know if there is much difference between the short drop and the long drop? My manual says the Lull I got should have a series 4000 short drop.? For some reason, this tranny is giving me problems on the other end as I have no high gear but low and 2nd seem to work great. If you have come across anything that might help that situation I would really appreciate a heads up. Thanks
 
M

Markmechman

New Member
Joined
Aug 6, 2015
Messages
1
Location
Wasco, ca
Joestewart I'd like to have a copy of the manual also. We have this transmission in our nut bank out wagons. We're having trouble with three forward gears. Reverse is fine. Dealership for Thomas said pressure was low and suggested new transmission. 5500.00 the unit only has 1800 hours! My email is Mark-a@att.net thanks for your help. Hope I can return the favor some day.
 
S

solutionserafin

New Member
Joined
Mar 15, 2016
Messages
4
Location
canada
Hi joe

joestewart said:
Thanks ISZ!

First thing I'm going to study is transmission fluid level - I've checked it fifty times, but I have trouble reading it because fluid seems to wick up the sides of the dipstick, and maybe I'm over reading it (interpreting it as full when its actually low)

Gonna measure some clutch pressures today, according to the algorithm given in the manual.

Attention everyone who owns a machine with the Funk 4000 transmission: I have the service manual on pdf! Approximately 120 pages. I can email it to whomever needs it.

Title: Assembly and Disassembly Funk 4000 Series Shift-o-matic Transmission

I was looking at the photos in this manual - the internals of this transmission remind me of the Ford C6 - the clutches, pistons and valve body appear similar. Except for its mass and weight and bulkiness, the rebuild probably would not be too painful.
Click to expand...

i would really need this funk 4000 shop manual is it possible tu send it to me by email at michel.c@serafincamion.com thanks!
 
D

davejo

Well-Known Member
Joined
Apr 3, 2016
Messages
104
Location
va
The farmer next door said I could give his Lull some TLC.

20160402_101310_zps4tnsvcr1.jpg


One complaint is that it only travels at a very slow speed. From the much appreciated links to the manual provided here, I guess I need to buy a test gauge and dig into the control valve:

20160402_123912_zpsydx0wflc.jpg


Here's what it looks like in real life:

20160403_135556_zpskykflne8.jpg
 
M

Micah Mccall

New Member
Joined
May 20, 2017
Messages
2
Location
Washington, KS
joestewart said:
Thanks ISZ!

First thing I'm going to study is transmission fluid level - I've checked it fifty times, but I have trouble reading it because fluid seems to wick up the sides of the dipstick, and maybe I'm over reading it (interpreting it as full when its actually low)

Gonna measure some clutch pressures today, according to the algorithm given in the manual.

Attention everyone who owns a machine with the Funk 4000 transmission: I have the service manual on pdf! Approximately 120 pages. I can email it to whomever needs it.

Title: Assembly and Disassembly Funk 4000 Series Shift-o-matic Transmission

I was looking at the photos in this manual - the internals of this transmission remind me of the Ford C6 - the clutches, pistons and valve body appear similar. Except for its mass and weight and bulkiness, the rebuild probably would not be too painful.
Click to expand...
I would really appreciate the funk 4000 service manual, if it's still available! My email is mccallmicah86@gmail.com
 
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