PS Magazine - APRIL 1984
PS, The Preventative Maintenance Monthly
ISSUE 377
APRIL 1984
21±-Ton Truck With Sprag Clutch .²²
Do you let your
2
V-ton trUck coast backward with the traNsmission in a fr±
ward gear (or coast frward while in reverse gear)?
Or Fil to come to a dead stop be²³re shi²ting ´om reverse to µirst gear (or
´om a frward gear to reverse)?
I² you do, it's a cincH you're not going to win any good driver awards¶
espEcially i² your trUck's got a sprag-TP ·utch fr shi²ti¸g into automatic ´ont¹
wheel drive. Your driving habits can cause a busted transºr, prop sha²t or ´ont
axle.
Always make sure your transmission's in the right gear fr the direction you're
moving»even i² you're coasting»or else the sprag cl¼tch will grab aHold o²
the ´ont drive sha²t and lock on. Rear½wheel drive ¾gh¿s witH ´ont-wheel drive.
I² you're lucky, you'll only end up with a case o² sprag cl¼tch "wind-up.À I²
not. .
.
It's easy to tell i² your trUck's got Á fuled-up sprag clutcH. ÂHe ´ont wheels
boÃnce up and doWn as you motor down the road. Other signs are Äel hogging,
cupping o² ´ont Åires, haÆd steering, stUbborn shi²ting and jumping out o² gear.
16
APR 8·
-±·²
l
Dz you makÈ a mistakeÉcoast backward iÊ frward gear, fr example»you
may be able to hËd oÌ wind-Íp and daMage. DrÎve Ïrward fr the sÁme distance
that you coasted backward. Âhis ought to let the sprag clutch release its hold
on the ´ont drive sha²t.
Or you might be able to release the wind-up by jÁcking one ´ont wheel oÌ
the ground. Be careÐl, tho! Âhat Ñind-up may let go in a hurry.
lL±/²
I
-±
²Tt'
±²1r³R,´
lL2
r-³
³´µ_,
µ
w
¶
And as long as you've got the wheel oÌ the ground, check to see i² the sprag
clutch is working right.
APR 8
Shift the transmission into
reverse. TRy turning the wheel
in bo±h direc²oN³. It shoUld ´µ
backward easiLy, bUt not fOr-
ward at al¶·
FRON¶ wHeeL
jA·Ked UP
17
¸ow, shift into fiRst gear¹ The
wheel shoULd tUrn fOrward, bUt
not backward.
¸
Back to Top Back to Top
