L 8000 Ford won't let me downshift

[D3DaveC]

I have a 1989 Ford L 8000 and can't downshift. 8 to 7 will shift with a slight grind but after that no way. Brazilian diesel with 10 speed. On the sun visor it says road ranger RT-7608 LOL . Stupid auto correct. Not lol. A guy suggested rear synchronizer. Can this be fixed with out taking the transmission out. What is it. Also a little sticky shifting up. Maybe I'm just a very poor driver? What to do? Thanks

 

[lantraxco]

Are you pushing the clutch in, and if so maybe too far?

 

[Birken Vogt]

I would see if you can find an old truck driver to take it for a spin and check out the technique required.

 

[repowerguy]

The only synchronizer in this trans is in the range section, all other shifts have to spliced in by you by double clutching or floating it in. Look for a old timer to take it for a spin and maybe give you some tips if need be.

 

[D3DaveC]

I know just the old timer to talk to. I remember double clutching the 1960 GMC 3 on the tree to down shift to first but the term floating is new to me.

 

[lantraxco]

Adjusting the engine revs slowly until she just slips into gear. Basically shifting without the clutch or just a touch to help cushion the load.

 

[repowerguy]

I sometimes forget that not everyone understands some of the slang I use. Floating is matching engine speed so the gear easily slips out then you let the rpm fall to get the next gear. The rpm gaps on a 10 speed should be 400 rpm or so.

 

[Delmer]

Buy or borrow an old Honda or Toyota with a stick and practice shifting that without the clutch, it's quicker, easier and cheaper practice than a truck.

 

[D3DaveC]

I talked to an old truck driver and he said he thought he would never learn to shift his truck but kept practicing. He said you need the correct rpm to shift maybe Rev just a little or drop rpm to shift. Thanks

 

[doublewide]

The road ranger 10 speed is a non syncro transmission. Double clutch or no clutch "power shift". Clutch to the floor may actuate the clutch brake, if it's not all worn out. Check this out;

https://www.youtube.com/watch?v=Ko0jSLtwuro

Practice, practice, practice.

 

[cdm123]

Also be aware that if you are on any sort of grade while you are concentrating ,or cursing, you may be losing or picking up speed and the gear you are trying to select may no longer be correct for the conditions. Some times in the beginning the right answer is pull over take a few breaths and start over from 1st.

 

[lantraxco]

The ones that always got me, in any big truck, were downhill into a corner with the brakes on hard, having to either shift several gears rapidly in succession or grab two or three holes in one shift, having to guess how far to go, LOL

 

[repowerguy]

The ones that always got me, in any big truck, were downhill into a corner with the brakes on hard, having to either shift several gears rapidly in succession or grab two or three holes in one shift, having to guess how far to go, LOL

Yeah! That's what separates the drivers from a steering wheel holder. With time you will know but until then you will have to use the tachometer and the speedometer to know how to grab two or three in a downshift.

 

[dieseldog5.9]

Look at the tag on the transmission for the model number, i drove an paystar with no gear in 7th position, it was a blank hole only on the high side, sounds stupid as high side is a repeat of the low side, I would guess the ratio worked for the low side but not the high as the shift decal had a blank for 7th position from factory. A broken main shaft retainer pin would cause a difficult shift at the break because the gear is not centered for the sliding clutch to engage. If you are not familiar with driving an eaton fuller transmission it may be difficult to diagnose faulty technique from a faulty transmission.

 

[doublewide]

Yeah! That's what separates the drivers from a steering wheel holder.

:lmao

 

[RZucker]

I have a '91 F800 with a 7.8l engine and a 6610 roadranger, approximately 250 rpm gear splits. It doesn't give you time to double clutch shifts unless you're skipping gears, throttle shifts only. Practice and it sounds like you're driving an automatic trans.

 

[D3DaveC]

The you tube videos were very helpful. I had no idea there is a clutch brake. Thanks to everyone for your help. I might have destroyed this transmission learning on my own.

 

[mitch504]

7608 LL is not a 10 speed, it is an 8 plus low and low-low (an 8LL).

You don't use the low position on the shifter in high range.

For down shifting you will always need to increase the speed of the input shaft of the transmission to match by revving the engine with foot off the clutch (either double clutching or floating) as a semi-old guy I could teach you in a little while in the truck, but not so easy at the keyboard.