BCS 735, gearing issues

[iphilgood]

Hey all,

This is my first post and I just recently bought my first (walk-behind) tractor.
It's a 90's 735 (with the ACME 10hp motor) that hadn't been used for about 5 years. Still in workable condition, but needs a little TLC.
I just tilled up about 1/4 acre with it.

The gearing was not what the indicator suggested and I had to find the "sweet spot" to disengage the clutch, but overall, it worked well.
The real issue was when I used the sickle bar mower and it kept popping out of the forward gear. So that swiftly put an end to my mowing.

Is this something that can be fixed in a few hours, or should I just stick to rear attachments until the season is over and then take it apart and dive in?
Also, I noticed the wheels are in the 'narrow' position. Is there a benefit to having them one way or another?

Great info on here. Been lurking for a few weeks.
Thanks for any info.

 

[farmerboybill]

Hi Phil,

Welcome to the forums.

There's a ball and spring in the shifter that holds the shifter in the gear you want. I'd look at that first. Maybe the ball isn't dropping into the hole for some reason. Usually that spring is too strong and it makes shifting difficult, but it sounds like you have the opposite problem.

Setting the tires at maximum width will add stability while mowing on hillsides. Narrowing them up allows you to use narrower implements and stay within the working width. Some attachments, like rotary plows and moldboard, plows are very sensitive to having the proper width. They will do poorly at the wrong setting and excellent at the right setting. I usually run my tires as wide as possible while staying within the width of the attachment.

I don't quite get your "sweet spot clutch disengagement". Usually it's a guessing game on whether you're in gear or in neutrals, as there's is a neutral between each gear.

 

[iphilgood]

Thanks so much for the reply.

What I meant by the "sweet spot clutch disengagement" is that when it's in gear, if I pull the clutch all the way to the handle, it doesn't always disengage. But if I let off slowly from there then it will disengage at some point; the sweet spot.

It is sometimes hard to shift as well. The rubber grommet holding the shift lever to the shifter often pops off, especially when engaging/disengaging the pto (I now just smack it with my hand at the bottom, and forgo the lever altogether, kind of annoying).

I'll double check to see if it's popping in the hole...if not, any suggestions as to next steps?

 

[farmerboybill]

Your clutch lever cable may be too tight. When you squeeze the lever, it's disengaging then re-engaging because you've shoved the shift fork too hard into the clutch.

The easiest fix for hard shifting is to take the ball and spring out and clip on coil off the spring. It'll then be strong enough to hold gear, but weak enough to ease shifting.

As far as it popping out of gear, I think you may not be getting the shift lever far enough to let that ball "lock" into its hole. Maybe the tab that keeps you from going into fast reverse is slightly bent back?

 

[iphilgood]

Okay, now I'm understanding a bit more.
The ball is in fact locking in the hole the sticker says is "F".
The problem is, it acts like neutral in that hole.
To get it to go forward (with front implements), I have to pull it past the "F" hole, but the tab keeps it from going to the next hole, so it sits between the two holes and then pops back into the "F" (which acts like neutral) hole after a little vibration.
The "N" hole acts like reverse, and it will not shift into the "R" hole.

If there was a cable involved, I'd say it is too tight, but since there aren't, what's the deal?
Thanks again for the help.

 

[farmerboybill]

I typed the last post a bit fast. I'm cleaning out chicken barn and don't have a lot of time to post, sorry.

The cable is on the clutch. You need to loosen it, either by screwing in the collar in front of the clutch lever on the handlebar, or by loosening the cable stop on the clutch fork on top of the transmission housing.

You should be able to adjust the tab on the transmission shifter by either loosening it and turning it, or by simply bending it. Once you've got it moved, it should stay in forward gear for mowing.

 

[iphilgood]

I adjusted the clutch cable, pretty straight forward.

The transmission shifter is more puzzling.
The ball does click in the hole for the forward gear. But when in that gear, it acts like neutral.
When in the hole for Neutral, the tractor moves in reverse.

If I pull it towards the motor until it hits the tab, the tractor will move forward, but cannot click into the hole the tab is blocking, which it shouldn't need to anyway.

It will not click in the hole furthest from the motor, which is supposed to be Reverse.
Feels as though it is very tight or stuck or something.
Not sure how to make transmission adjustments.

 

[wstr75]

I have a 737 and it has a straight line shifter like the 735. To get its shifter to go into all gears, I loosened the two bolts holding the shifter indicator/detent assembly and gently tapped the detent assembly back & forth while selecting gears & neutral positions until the sweet spot was found. I then fully tightened the detent assembly bolts. I determined the gear & neutral positions by rocking the tractor back & forth as each detent position was tried.

The other big discovery was the type of grease applied to the detent assembly makes a BIG difference! I initially liberally greased the detent holes with a non-moly grease and could not easily shift my shortened ball spring shifter. This was frustrating as I had already cut the recommended amount off the original spring. I then wiped off that grease and next slathered on grease containing molybdenum disulfide. The shifter immediately shifted beautifully! From now on my grease gun will only have really slick high quotient moly grease!
Bill in NC

 

[iphilgood]

wow Bill, thanks so much.
It's been really frustrating walking past the BCS and not knowing what to do next.

Am I correct in assuming the detent assembly is just the metal bracket with the holes that the spring-ball pops into?
I think I understand what you're saying.

And the area you greased is just the bracket and holes? I'm surprised that makes such a difference.
But happy to hear I may not have to open up the tranny.

I'll give it a try and then post here with results.
Thanks.

 

[wstr75]

Yes and yes to both questions.

 

[iphilgood]

Ok.

I loosened the bolts and fiddled with the detent assembly.
Once, it slipped into the hole furthest from the motor, but only once.
I could not get it into that hole a second time.
This was all done with the motor off.

 

[farmerboybill]

Shifting these machines is like shifting a manual transmssion car. Sometimes you need to feather the clutch to get it into the desired gear. Without the engine running, you can't feather the clutch, but you could do the next best thing - rocking it back and forth while pushing or pulling on the lever. Were you rocking it back and forth while trying to get it into first?