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View Full Version : No engine compression in 2nd in a T-86..



dan0
06-12-2007, 08:19 PM
Guys-
Is it normal not to have much engine compression braking in 2nd gear in this T-86 in my 2R11?
Seems like it just wants to coast...where in the ol truck trans it definetly had engine compression that acted as a brake...
Different to drive now.[:p]

dan0

Herd:
06 Jetta TDI
1941 M15
1953 2R11
2001 F-350
1989 Caprice
Deere's:
67' 112H
88' 332

N8N
06-12-2007, 08:21 PM
Did you swap from a straight three speed to an OD trans? If so, perfectly normal. There is no engine braking until the OD engages. If you anticipate a need for engine braking, lock out the OD before you start out.

nate

--
55 Commander Starlight
http://members.cox.net/njnagel

PackardV8
06-12-2007, 09:43 PM
Greetings,dan0,

Actually, if the OD is working properly and you are in third gear with the OD engaged and downshift to second, you will have compression braking down to the OD disengagement point, usually about 28mph. Just when you are coming up on that downhill hairpin turn and you are busy with steering, the OD will disengage and you sail off into the weeds.

As N8N says, lock out the OD if you don't want to play.

thnx, jv.

PackardV8

dan0
06-12-2007, 10:09 PM
Guys-
I have not enen connected the OD Sol yet...just aint used to coastin' so much...where's my eng compression...?
Big difference ..I've been double-clutchin' for nearly 6 yrs!
dan0

Herd:
06 Jetta TDI
1941 M15
1953 2R11
2001 F-350
1989 Caprice
Deere's:
67' 112H
88' 332

Dick Steinkamp
06-12-2007, 10:26 PM
quote:Originally posted by dan0

Guys-
I have not enen connected the OD Sol yet


That won't stop it from free wheeling IF the overdrive handle is pushed in. Pull it out and try it. If you haven't hooked that up yet, go under the car and move the lever the OD cable attaches to forward. That will take it out of OD and you should then have a normal 3 speed trans (with engine braking).

http://thenobot.org/images/s2d/s2d_01.jpg

dictator27
06-12-2007, 10:34 PM
What Dick said. The solenoid does nothing until vehicle speed is about 28-32 mph. Below that speed with the control pushed in, the vehicle will freewheel. Shifting down to 2nd gear below that speed won't do anything. The up side is once you are rolling you can change gears without using the clutch pedal until the solenoid engages.:D

Terry

dan0
06-12-2007, 11:28 PM
Guys-
Correct; I don't have the cable attached yet[:I] Do I understand correctly I have OD now with the lock-out lever pushed aft?
I know, GREENHORN![:p]
dan0

Herd:
06 Jetta TDI
1941 M15
1953 2R11
2001 F-350
1989 Caprice
Deere's:
67' 112H
88' 332

dictator27
06-13-2007, 01:04 AM
yep

Terry

gordr
06-13-2007, 03:12 AM
quote:Originally posted by dan0

Guys-
Correct; I don't have the cable attached yet[:I] Do I understand correctly I have OD now with the lock-out lever pushed aft?
I know, GREENHORN![:p]
dan0

Herd:
06 Jetta TDI
1941 M15
1953 2R11
2001 F-350
1989 Caprice
Deere's:
67' 112H
88' 332


Unless the solenoid is connected and working, you don't have overdrive, but you do have free-wheeling. The rear-most unit in the overdrive case is the over-running (sprag) clutch, which allows the engine to drive the wheels, but won't let the wheels drive the engine. It is needed to take the torque load off the driveline so the solenoid can shift the overdrive in or out. When you pull the lockout handle out (lockout lever forward), the sun gear is moved back, and effectively bridges across the over-running clutch, locking it up. Useful for mountain driving!

In a normally-operating overdrive, freewheeling is only in effect in direct drive, below the OD cut-in speed. Once the overdrive engages, you have two-way torque transfer in the transmission again. You won't see much engine braking in 3rd OD, because of the gear ratios involved, but it IS there.

Incidentally, when you shift to reverse, the overdrive shift rail is pushed back by a cam on the first-reverse detent sector, effecting the same lockout action as the manual lockout cable provides. Were this not so, you'd have no reverse, as the over-running clutch can't transmit torque in reverse. It's always good practice to leave an OD-equipped car in Reverse when parked, so it won't roll away.

Gord Richmond, within Weasel range of the Alberta Badlands