More Speed for Cub Cadet LT1040 CVT?

Budget_gokart wrote:

did you change front and rear belts? and both pullies or just one im confused

As per your instructions I took off the stock 7.25 inch rear pulley and replaced it with a 5 inch rear pulley, which also meant replacing the rear belt that is now connected to the new 5 inch pulley.

Nevadablue wrote:

The new belts appear to be ‘A’ size. The old belt is noticeably wider. Your best bet, IMO, would be to find ‘B’ size belts.

And so goes my learning curve.
Thanks for the feedback Nevadablue.

Time to find and try ‘B’ size belts.

Tractor supply should have 5/8 wide belts that are interchangeable with B belts, if not the same. You should be able to pick up B belts from most any rubber supplier hardware store.

Make sure you don't get a fractional horsepower belt, kevlar or aramid is preferable. FHP belts will tear up fast especially with this variable sheave system.

RichieRichOverdrive wrote:

Tractor supply should have 5/8 wide belts that are interchangeable with B belts, if not the same. You should be able to pick up B belts from most any rubber supplier  hardware store.

Make sure you don't get a fractional horsepower belt, kevlar or aramid is preferable. FHP belts will tear up fast especially with this variable sheave system.

Thanks RichieRichOverdrive for the tip with looking for belts.

i cant wait for you to get it al done up i love messing with mtds but moved on to better tractors LOL

Hello Good People,

So here is my update thus far.
With the new 5inch rear pulley combined with its new A35 V-belt the mower did not move faster. What I was getting was some slow forward movement without applying the accelerating pedal, same with reverse.

Replaced the A35 V-belt with a wider B36 V-belt. This time I noticed a bit more movement than with the A35 belt. Still not any faster whatsoever as I have my foot jammed into the accelerator pedal.

What should I be looking for at this point?
It feels like I may have had faster speed with the stock 7.25 pulley and stock belt. So far no speed increase has come thus far.

T.I.A.

Possibly is the belt slipping?

I dont think so...I replaced the A V-belt with a wider B V-belt.

I will make sure the nut on the pulley is torqued down. Would a loose nut on the pulley cause belt slipping?

Aside from my big shaft drive White my knowledge of MTDs is slim, but I found this video and I think it may be helpful. If all else fails you could retrofit a torque converter and use a straight belt or chain to the transaxle.

If I'm correct, I believe there are two belts on these, and the first goes back to the top of the variator, and is a 1/2. The second goes to the transaxle and is a 5/8. Then again it's been a while so take that with a grain of salt. Or the whole shaker, that might be better.

Do some research on the net. I believe you will find that most if not all people who attempted to mess with the variable pulley and pulley swaps failed. I wish you luck.
If you do succeed, please post your solution. I have several variable pulleys set aside and have considered welding one into a solid double pulley to use as a ‘jackshaft’, or cutting one up to make small pulleys, but not for use as a drive unit in stock configuration.

Thanks again Everyone for the response.

I will keep trying. With the feedback it sounds as if there is not much I can do to this CVT riding tractor to increase the speed. Before joining the forum I spent a month watch dozens of YouTube videos.

Might as well remove the electric PTO clutch since I do not plan on returning the mowing deck.

i made my troy with the same chassis go quite a bit faster then stock it just creeped because i think my belt was too tight but it must have been a chassis issue i plan to get another one if i can there s the same mower down the street i was offered i might go offer a small bit of cash for it. you should only have to change the rear belt and use the stock front belt if the belt fits banjo tight in the rear with the rear tensioner pully you should be fine

Let me get this straight.... your saying to increase me speed I should only need good-tight rear belt on the newly installed 5inch rear pulley and that’s it?

No need to touch the front belt?

yes did you change the front? that model has a stationary variator if the rear belt is tight and the the front belt is the stock one you should be fine

Personally if you really want the speed increase and this doesn’t work out I recommend looking around for a craftsman II or the like. Easy to swap pulleys, no variator, nice and reliable all around. Just my 2c

Rustbucket Garage wrote:

Personally if you really want the speed increase and this doesn’t work out I recommend looking around for a craftsman II or the like. Easy to swap pulleys, no variator, nice and reliable all around. Just my 2c

The front was never touched. You did not recommend doing anything to the front. You only mentioned installing a smaller rear pulley and rear belt.

So first off, on all MTDs with the FNR like yours, the rear pulley is already around 6 or 7 inches in diameter. Hence why the 5 inch is not creating much of a difference. However, it should be a little bit faster. Maybe not enough to notice but it should be somewhat faster. So, as some have already mentioned, double check that the rear belt is tight. Even if it has just a tad bit of slop, that could cause belt slip. Just about anything on MTDs can.

The creeping issue is probably due to the front belt being slightly too tight. There is a way to adjust the clutch on those. If it is not creeping much, I would adjust that. If it is creeping quite a bit, then you should probably get a front belt that is 1/2" bigger, IF, the rear belt is tight.

But that half inch bigger belt won't matter if you really want more speed. If you want to continue with the speed increase, then you should go ahead and put a bigger front pulley on. A 5 inch would be good on the front. You can get the right pulley from tractor supply if your motor is not a Kohler. Then of course you could go ahead and get a bigger front belt.

The newest wider B V-belt in the rear fit is very snug, so snub it was a challenge attaching the rear spring once the belt was installed.

thats how it should be so whats the result? also is the tractor moving or not?

Budget_gokart wrote:

thats how it should be so whats the result? also is the tractor moving or not?

Just reporting the details, nothing new beyond what was already written.

Yes the tractor does drive forward and in reverse, just not a noticeable speed increase.

bigger then factory rear tires also give quite a speed increase

Budget_gokart wrote:

bigger then factory rear tires also give quite a speed increase

Thanks for the added tip.

i built 3 MTD yard machines. my troy bilt had the same chassis it was fast and a monster at offroading i had swapped the front and the belt kept falling off it ended up blowing the transmission from me doing neutral drop wheelies and no mercy reversies. so i obliterated the imputshaft. then i built "rocket" it was a very very very basic low model yard machines i paid 60$ for put my troy bilts 17.5 briggs and absolutely had a blast with it again front pully from my troy bilt it was fast wheelies etc 5 inch front pully and bigger rear tires kept kicking the belt so neutral drops regularly. it was in brand new condition it was like a 2000 something newest chassis available from mtd. i tried to take it to the haspin meet but had carb troubles so i left it behind and took, "rocket #2" aka rocket turd when it was "stock".
14hp briggs and a deck pully welded to the splined piece for the rear pully and it went to haspin and dropped a valve smoked the belt bent a wheel hub blew a tire and the whole front end fell off and i completely totaled it. then body swapped it onto the same chassis as rocket #1 and sold rocket #1 to some kid in town for 10$ with no motor. then when i blew the belt for the final time and couldnt get the money together i parted out rocket #2 and scrapped it and got a craftsman finnaly. and now ive got a double pully swapped 12hp 6 speed manual craftsman thats an absolute monster

Got any images to share since I am a visual creature?

Thanks

plenty but i have to upload them later. they also are in budgets tractor builds
https://www.atltf.com/t6640p50-budgets-tractor-builds#117225

Cool!