D125 stretched belt?

gmankiew

Forum Newbie
Joined
Nov 16, 2021
Threads
3
Messages
5
D125 mower drive belt (not the deck belt) seems to hav stretched. All the parts look like they're working but the belt won't contact the pulleys.Anyone have any ideas before I buy another belt or tension spring? Can they stretch without breaking?

NEW ...... After further inspection, I found that the CLUTCH ROD is not moving when the pedals are moved.The rod is attached to the idler pulley bracket. Can't see what the other end is connected too, can't see anything moving even when looking from the top with the battery removed. Thinking it's time for the pro's??
 
Last edited:

bertsmobile1

Lawn Royalty
Joined
Nov 29, 2014
Threads
64
Messages
24,647
Kevlar belts do not stretch more than 0.5% or if you like that is 1/2" per 100 inches and that amount of stretch makes no difference to their operation.
They do wear thin and when thin the sit deeper in the pulley and sitting 1/4" deeper in a pulley is equivalent to being 2 to 4" too long .
Usually when a new belt seems way too long it is because the owner has routed it the wrong way through the clutching pulleys .
Next problem is the belt being wrong from the start ( wrong part number or mislabled )
After that there is wear in the V pulleys a very small amount of wear in the grooves makes a massive difference to the tension in the belt .
With the exception of the locally made mowers which don't use belt clutching I replace all of the idlers with every 2nd belt.
And 6 to 10 belts will be a new stack pulley and 10-15 belts will be a new tranny pulley
And before you ask, the stack pulley is very small so it wears faster than the tranny pulley
 

bertsmobile1

Lawn Royalty
Joined
Nov 29, 2014
Threads
64
Messages
24,647
A deceptive piece of marketing
"Off the shelf" is actually standard fan belts, not Off the shelf Kevlar Lawn & Garden belts.
I am sure Gates would argue the point considering they make over 1000 "off the shelf" Kevlar Lawn & garden belts as well as around the same number of OEM spec replacement belts .
About the only real difference I have found is the siz & placement of the reinforcement cords.
Some cheap belts will have 3 thick ones rather than 7 or 8 thin ones.
And highly serpentine belts will have the cords almost in the middle of the depth
 

bkeller500

Well-Known Member
Joined
Jul 2, 2018
Threads
7
Messages
285
OEM belts........They tend to last longer and you are always at factory specs. More expensive but worth it.
 

Hammermechanicman

Lawn Addict
Joined
Jan 10, 2020
Threads
49
Messages
3,485
Belts are all over the place. The last OEM belt i bought from a reputable on-line suppy house was marked MTD in a MTD sleeve and also said "made in india" worked just fine. Last couple of house brand OEM equivalent belt from same supplier we marked "made in USA". Used some other made in India OEM equivalent belts that worked just fine. Did have a customer bring in his own belt he got off Amazon that had no markings and looked so crappy i told him i wouldn't put it on.
 

VRR.DYNDNS>BIZ

Well-Known Member
Joined
Jul 17, 2016
Threads
1
Messages
188
Belts are all over the place. The last OEM belt i bought from a reputable on-line suppy house was marked MTD in a MTD sleeve and also said "made in india" worked just fine. Last couple of house brand OEM equivalent belt from same supplier we marked "made in USA". Used some other made in India OEM equivalent belts that worked just fine. Did have a customer bring in his own belt he got off Amazon that had no markings and looked so crappy i told him i wouldn't put it on.
Yes belts are all over the place. So are applications and thier ability to accommodate belts of various specs. Some are very finnicky and some not so much. Also OEM's are often making belts at fractions and different vee angles to force proper fit to be an OEM belt. Then aftermarket copies the OEM description and has made a belt as described but not a match because OEM lied. In my opinion, and experienced small engine mechanic will know when and what substitutes may be advised or may to be confident only go OEM.
 

bertsmobile1

Lawn Royalty
Joined
Nov 29, 2014
Threads
64
Messages
24,647
D125 mower drive belt (not the deck belt) seems to hav stretched. All the parts look like they're working but the belt won't contact the pulleys.Anyone have any ideas before I buy another belt or tension spring? Can they stretch without breaking?

NEW ...... After further inspection, I found that the CLUTCH ROD is not moving when the pedals are moved.The rod is attached to the idler pulley bracket. Can't see what the other end is connected too, can't see anything moving even when looking from the top with the battery removed. Thinking it's time for the pro's??
We seem to have gotten off on a belt tangent and lost the plot a bit
The clutch / brake pedal is connected to the clutch rod # GX23121 which is quite short.
The clutch rod pulls the tensioner plate with the 2 pulleys on it forward against the drive spring # GX23594
the spring has a Z bend where it connects to the tensioner plate ( arm ) and is prone to falling off so then there is no drive when the pedal is released .
The brake rod # GX22747 is also connected to the clutch / brake pedal but it goes all the way back t the transmission to operate the brake
That is the one you can see under the battery box and should only move with the final 1/3 of pedal travel it is adjusted by a nut on the end of the rod which tensions a spring between the nut & the connection pin.
They do not move when the F & R pedals are moved, only when the clutch / brake pedal is moved .
JD have their owners manual on line and that has better service information in it than most repair manuals have .
On top of that JD make a technical manual which will turn a mechanical idiot into an accomplished mechanic overnight so is worth much more than you pay for it .
 
Top