Toploader at the Track

fastd · #1 (**permalink**) 03-06-2012, 12:46 PM

Anyone have any advice for track prepping a 4 speed toploader. I went to the track the other day and after about 10-15 minutes transmission got very difficult to shift.

I think it got hot; I am going to try to add a temp gauge to the transmission gear oil. Any opinions about optimal fluid temp? I searched Stewart Warner for a transmission oil temp gauge but couldn't find anything. Does SW make a gauge; I figure it would not get nearly as hot as engine oil.

Any thoughts are appreciated.

Regards,

Phil (fastd)

Barnsnake · #2 (**permalink**) 03-06-2012, 06:43 PM

Are you sure it was the transmission and not the hydraulic clutch fluid boiling and reducing the disengagement stroke?

fastd · #3 (**permalink**) 03-06-2012, 07:37 PM

jim
maybe its the hydraulic clutch fluid. i dont think so though. i had just replaced the dot 3 with high temp fluid and the clutch pedal felt ok.

has anyone ever been able to overhead their toploader gear oil?

phil

RICK LAKE · #4 (**permalink**) 03-07-2012, 04:32 AM

fastd Phil it's a heat soak problem. I have had this problem years past, 15 minutes and the trans starts to not want to shift. The fluid also gets warm for the clutch. I doubt that the clutch fluid is boiling but if your fluids only have one little tank for both brakes and clutch this COULD be a small problem.
Here's what I have gone through over the years and ended up with
If you have inward rear brakes, there is alot of heat generated from them. Also the same applies for the motor and trans in the trans tunnel. This air has not where to go and stays there. I have an added fire shield on my tunnel just in case. You have 2 choices for a fix,
Add a cooler, pump and fan kit for the trans fluid and run it at the track only times. this is about a $600.00 kit plus lines and connectors.
The idea I use is to add 3 bildge fans under the hood to remove the air. I use the r/s air hose from the front to a 3" blidge fans mounts on the r/s foot box to blow air down the tunnel. A small hose comes off the back side. This work well with fresh air outside of the car. I also added 2 more 4" , 1 on each side of the motor compartment to well remove the hot air under the hood. They blow the air out the louvers in the fenders. You need to do a little wiring, couple of relays, and switches. Each fan pulls about 3-8 amps demending on heat. Here's the other problem with 3 fans you will not have enough charging ampage to run everything in the car and these 3 fans. Need to go to a min of a 95 amp alt, and change over the amp gauge to a voltage gauge on the dash. running this much ampage through an amp gauage will cook the insolator on the gauge over time. This happened to me. P-M for more info. This fixed my over heating problem. Rick L. Ps I am still going to run a rearend oil cooler in the car.

fastd · #5 (**permalink**) 03-07-2012, 09:51 AM

Rick,

Thanks (as always) for your insights.

I have looked for coolers for manual toploader transmission but haven't been able to find any. If that set up is $600, wondering if I should try to upgrade to a 5 speed that won't overheat...or do you think any transmission will overheat given the lack of air flow?

A 5 speed might be sweet in this car; right now I have a 4 speed with 3.50 rear gears, if I went to a 5 speed and could put the 4.11s back in there, very curious what that would do to performance.

Regards,

Phil

FatBoy · #6 (**permalink**) 03-07-2012, 11:59 AM

I'm by no means a expert on these matters, but I have a Toploader on my Kirkham and after a hard day at the track, I had no such problems with mine and I don't ever recall hearing about gearbox cooling problems on original race cars.
Could it be that the shifter linkages aren't correctly adjusted and the extra heat is exacerbating the problem? I think it would be worth checking the linkages first to make sure they are spot on.

Paul

Clois Harlan · #7 (**permalink**) 03-07-2012, 01:30 PM

I tend to agree with Paul. I have ran my Cobra at Road America in August for upwards of 30 minutes at a time and never had a problem. I have had the same trany in my car for over 10 years and the ONLY problem I ever had was when I was drag racing and I twisted the input shaft in two pieces on launch. $350 and everything was as good as new. I would check linkage alignment first and then check and see if your clutch is fully disengaging/engaging. You may need to adjust your play on your hydraulic clutch.

Clois

fastd · #8 (**permalink**) 03-07-2012, 01:42 PM

I am having a little trouble conceptualizing linkage to overheating if the linkage works fine when cool. please help/explain.

PeteF · #9 (**permalink**) 03-07-2012, 02:22 PM

Has the transmission been through recent maintenance/rebuild ? Could be improper assembly if so. Are you sure it has the correct fluid, and is filled to the overflow plug? I believe toploaders use old fashioned heavy gear oil, not automatic transmission fluid like some newer transmissions. Is your driveshaft length correctly allowing for slippage of the output yoke, as the engine gets hot and grows rearward. Check for any other mechanical binding/interference under the tunnel. Like others who have commented, I have never heard of fluid getting that hot to cause a shifting problem. I don't think Shelby used trans coolers at LeMans. (someone will correct me if I am wrong) Sounds like something is binding due to thermal growth, either internal or external to the tranny. One last thought, are you running a hydraulic (internal) throwout bearing? Some have had problems with those. Good luck.

fastd · #10 (**permalink**) 03-07-2012, 03:54 PM

Thanks for all of your input; i need to go back to check out a few things.

Primarily I think I have pretty strong confirmation from you all that toploaders should be OK at the track and that the problem is with my set up.

fastd · #11 (**permalink**) 03-07-2012, 07:27 PM

maybe this is causing my problem: we installed a puke can on the transmission but neglected to vent it. shouldnt that cause a substantial heat build up?

Bobcat · #12 (**permalink**) 03-07-2012, 07:48 PM

I`ve got a top loader in my 63 1/2 Galaxie 427 . Tranny became hard to shift after about 15 to 20 minutes street driving and difficult to get into first at a light . I had changed oil a while back and had to use the GL4/GL5 that is supposed to be ok ( could`t find any GL4 oil ) . Guess what ? It isn`t the same . A top loader needs a true GL4 . The GL5 has a higher sulphur content than the GL4 and can/will damage the brass synchos , causing hard shifting . Finally found a true GL4 oil at NAPA and will be changing it out shortly .

DAVID GAGNARD · #13 (**permalink**) 03-07-2012, 09:40 PM

Same as Clois/Paul for me, running a 47 year old toploader,had it gone thru 8 or 9 years ago, it is in my road race car, running races from 15 to 30 minutes of all out racing as hard as I can, never have had any problems, soo far, knock on wood!!!!!!!!!!!!!!

It will and does get hot at a track session, I've put my hand on the case just to see,but never have had a shifting problem from cold start to the end of a 30 minute race.........

I use 75/90 Valvoline gear oil in as per the guy that rebuilt it.......I change the oil in it at the start of each race season,thats all I've done to it in 8 racing seasons.....

David