transmission problem hard shifting when warmed up. Any ideas no problems when cold.


Oct 15, 2014
16
Hi Guys.
Just wondered if any owners out there have experienced difficult gear changes up and down the transmission when the transmission has got up to operating temperature.
I've tried different brands of oil. Replaced the selector which had some slack in its movement. replaced the gear lever which had some stiffness in the ball joint whilst disconnected from the selector cables. (Cables move very freely detached).
There is no clutch problems or difficulties in clearance. I'm thinking it's down to possible worn inner workings of the transmiss gears selectors caused from hard driving abuse!
I'm up for rebuilding the transmission. any recommendations where I can get parts? Or better still an upgrade complete transmission if there is one in the market.
The car has covered 25,000 miles now. Running approx. 600hp.
I also have a power problem which I will post separately.
 

jcthorne

GT Owner
Aug 30, 2011
792
Houston
Have you flushed and bled the clutch fluid?
 
Oct 15, 2014
16
Hi, thanks for the post, yes the clutch has been bleed many times, operation of the clutch pedal and clearance feels good, the clutch i am told was replaced approx. 3 years ago, around mid mileage to what it is today, but that was only done i believe as the transmission could have been removed due to drive shaft flange bolts breaking in its earlier period of owner use, but that was before my time in looking after this car. I've only been working on this car since 19,000miles onwards.
 

zach05855

GT Owner
Oct 16, 2012
222
Calgary, Alberta
What fluid are you using in your Gearbox.??

You mentioned that you have tried different brands of fluid
 
Oct 15, 2014
16
Currently I am using Castrol Long Life syntrax 75w-90, I've used previously another castrol gear oil, syntrans multivehicle 75w-90 and fuchs titan race 75w-90 syn 5, Neo HD fully synthetic 75/90 gear oil. and possibly one or two other oils in the past. as Dave from GT101 suggested, it could well be the selector cables after all, I Don't recall checking them immediately after a test run in recent months (but I could be wrong), they could be difficult to move as the cables run directly over the top of the engine under the supercharger and could be damaged from the heat build up over the years(so when hot they could be restrictive in movement, will check later today, i have new ones in stock, but did not replace due to waiting to renew the supercharger for an upgraded polished one. i will try to replace the cables early next week to see if that makes a difference.

today we are fitting the trans cooler kit, which will help keep the transmission a tad cooler. Thailand summer months can be very hard on the oils especially when running the car fast.
will keep you updated,

What oils by the way are other people using for fast road/track style driving? and in hotter climates?
 

BlackICE

GT Owner
Nov 2, 2005
1,416
SF Bay Area in California
Most all of us are only using the recommended Ford oil in the transaxle.

Since you have been using a variety of oil it may not be a bad idea to send a sample of the transaxle oil for analysis.
 
Oct 15, 2014
16
Hi Guys, I've just changed over the gear selector cables, the old ones were melted, so this for sure was causing my issues when the temps increased the cables would have loads of friction. will be testing later today if the weather improves. will update to confirm all is ok on the transmission side of things. just power issue to over come now.
 
Oct 15, 2014
16
Changing the gear cables worked! so a combination of wear and tear on gear shifter level(already replaced), gear control unit quite a bit of play in the movement, (already replaced) and finally the most important part that caused the hard shifting when hot, gear cables. the outer casing was totally destroyed by the heat build up, im surprised they worked so good when cold! ok so this is a successful fix. :)
 

twobjshelbys

GT Owner
Jul 26, 2010
6,053
Las Vegas, NV
Thanks for reporting the solution!!! It wasn't my expected list. Are they in the consumables list (like brake pads)?
 

PL510*Jeff

Well-known member
Mark IV Lifetime
Le Mans 2010 Supporter
Nov 3, 2005
4,876
Renton, Washington
Thanks for reporting the solution!!! It wasn't my expected list. Are they in the consumables list (like brake pads)?
The shifter cables are routed through the valley of the engine. The outer jacket covering degrades with so much engine heat , causing the inner workings to bind up due to the lubricant in the cable assembly to bleed out through the spiral metal "jacket".

I had forgotten about this glitch in the giddy up. Or I would have posted up sooner.

When we replaced the cables in my GT we wrapped them with heat pad material and double wrapped that with a double layer of heat tape, and when re-installed we modified the cable holder/standoff a bit to allow for no direct contact with the engine block. As I remember, my tech Greg, said it took him over 2 hours to pry/scrape the cable assembly from the block.

This "fix" has worked successfully in my GT with no shifting problems in over the last 90,000 miles.
 

nota4re

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Feb 15, 2006
4,177
This "fix" has worked successfully in my GT with no shifting problems in over the last 90,000 miles.

I wouldn't believe anything Jeff says. Everyone knows that supercars cant be driven 90,000+ miles! He MUST be making this stuff up. :)
 

PeteK

GT Owner
Mark II Lifetime
Apr 18, 2014
2,268
Kalama, Free part of WA State
That info makes me want to wrap my shifter cables preemptively. 'Course, I only have 30Kmi on mine (so far).
 

Bart Carter

GT Owner
Mar 12, 2006
272
Las Vegas
Could the cable problem cause the "crunch" shifting from 1st to 2nd? The same problem does not occur when shifting from 3rd to 2nd.
 

twobjshelbys

GT Owner
Jul 26, 2010
6,053
Las Vegas, NV
Could the cable problem cause the "crunch" shifting from 1st to 2nd? The same problem does not occur when shifting from 3rd to 2nd.

Does your hard shifting 1-2 happen just after starting (cold) go away when the car is warmed up?
 

Bart Carter

GT Owner
Mar 12, 2006
272
Las Vegas
It gets a little better, but does not go away.
 

twobjshelbys

GT Owner
Jul 26, 2010
6,053
Las Vegas, NV
Mine goes away as the engine and transaxle fluid warm up. I think there is a topic on this already and I thought it was recommended to flush and replace transaxle fluid
 

Bart Carter

GT Owner
Mar 12, 2006
272
Las Vegas
Mine goes away as the engine and transaxle fluid warm up. I think there is a topic on this already and I thought it was recommended to flush and replace transaxle fluid
Did that and it was better. But still cannot get rid of the 1-2 crunch completely. Hence the cable question.
 

nota4re

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Feb 15, 2006
4,177
Bart, I would try bleeding the clutch as it would be higher likelihood of being your problem.
 

SMOKDU

GT Owner
Dec 17, 2011
412
Good stuff. Did you ever find out the over heating issue and lack of power? I thought it was the intercooler pump. What did it turn out to be? You never updated that post as far is I can see. Sorry if you did.
 

Bart Carter

GT Owner
Mar 12, 2006
272
Las Vegas
Bart, I would try bleeding the clutch as it would be higher likelihood of being your problem.
Thanks, didn't think that it was a clutch bleed issue as no other gears were a problem. When it gets warmer, I will bleed.