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Author Topic:   transmission
chevelle
Dirt Full Roller

Total posts: 71
posted November 16, 2003 02:23 AM  
I am building my first car, and am going to run a Turbo 350 trans. My question is what should I do to a used tranny to prepare it for the races. I plan on at least changing the fluid and filter, and possibly having someone that knows trannys look it over.
Thanks

dan ferry
Dirt Maniac

Total posts: 183
posted November 16, 2003 05:19 PM  
id definitely add tranny cooler

racer17j
Dirt Forum Champ
Total posts: 5390
posted November 16, 2003 08:07 PM  
It makes a diff. what gear you run in. Seems to me that the guys that run in low gear have a lot more probs. I have one with 3 seasons on it running in second. The only thing we did for a cooler was run the lines down the frame rail for a short distance. All this with 1 fluid change about mid season.

redneck racing
Dirt Forum Champ
Total posts: 860
posted November 16, 2003 09:22 PM  
Is a tranny cooler necessary to use when only running a 25 lap main or do you absolutely need it. Eddie

racer17j
Dirt Forum Champ
Total posts: 5390
posted November 16, 2003 10:06 PM  
A cooler is not absolutely essential if you change the fluid often. I run a temp gauge in mine (in the drain plug of the pan) and with 1 B&M 19,00 GVW cooler it would peg the gauge at 270 degrees after about 8 laps (cooler mounted in front of rad, ductwork in place). Tranny fluid will start to break down when it gets much over 240-250 and seals will start deteriorating around 300. I'm guessing it was getting up to 300+ by the end of a 15-20 lap race.

So, I added a 2nd cooler in series and a Summit deep aluminum pan (+2 qt). This keeps temps around 210-240 even during a 30 lap race with about 10 cautions. Oh... and this is running a 'glide with a TCI circletrack 2600ish rpm convertor. A stock convertor wouldn't make as much heat.

I've run the same internal parts (in like 5 cases until I bought the Dedenbear in July) and even reused the Pennzoil synblend fluid all year. The clutches are still perfect after now 2 years of racing.

So, that's just my experiences and I'll always run a cooler(s). If the valvebody is setup right and the pump is in good shape, pressure should never be an issue. If the couple PSI you lose through a cooler makes it fail, you have other problems that need attended too.

I'd recommend having the valvebody setup for full manual control and hard shifts. Stock slushbox shifts will murder the clutches in a hurry no matter what else you do.

[This message has been edited by Raz_900 (edited November 17, 2003).]

wizzard
Dirt Freak

Total posts: 306
posted November 17, 2003 11:37 AM  
i agrre wit h 17j and raz cuz a cooler does keep the temp down but it also gives more places for leaks and presure loss so i geuss your d***ed if ya do and d***ed if ya dont when i use a used trans i always put in new seals and a manual valve body kit,new fulid.but to tell ya the truth how many good old style th350's are out there that dont have 100,000 miles on them so latly i just do a 200$rebuild on them

doubletrouble
Dirt Forum Racer

Total posts: 82
posted November 22, 2003 11:53 AM  
I have to for once disagree with you guys.We run a TH350 in our pure stock.Was newly built and had only 3 races on it when it went ,all clutches burnt up.We were running our coolent lines to the raditor stock set-up.IN low gear the tranny got to hot,I was later told after new tranny put in to run small fire wall mounted cooler,its really shorter lines and less chance for leaks and it was cheap....cheaper then a nother tranny

racer17j
Dirt Forum Champ
Total posts: 5390
posted November 22, 2003 01:03 PM  
yes if you run in first gear you may want to i run 2nd with a 3.73 gear the one i smoked i ran in 1st with 2.28 lasted 2 nites and the clutches were fine the gear tame apart on the output shaft. but i get about 50 nites out a tranny that i have less then 75 bucks in most times so thats not to bad these guys have them gone tru and run the cooler and still go thru them most times the pumps are what takes a crap on them

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