Replacement TH350
Thread Starter
Burning Brakes
Joined: Nov 2017
Posts: 778
Likes: 112
From: Redneck Riviera, FL
Replacement TH350
i need to source a transmission for a less than 300hp application and was considering a house brand from summit or jegs. i'm hoping someone with personal experience can speak to the quality of the remanufactured trannys from these companies. they both have great return policies but it would still be a real pita to have to pull it and ship it back. thanks.
Last edited by 3154tm; Nov 30, 2019 at 09:35 AM.
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
OP
Seems you're looking for minimal power capability ... why not seek recommendations for a great builder near your city ? ... local ...
Not necessarily a "race" shop ... a good local shop with a solid rep for long-lived builds and complete face-to-face service.
Perhaps you're near Eglin AF Base / Ft Walton Beach / Freeport ? I know the area, But No, I don't have a tip there ... but someone probably does.
Any Warranty issues become quite biased in favor of supplier when dealing with an out-of-state supplier ...
... the buyer has much more clout when the supplier is also subject to same state Court system (i.e. supplier has a physical presence within your state).
I agree, an auto w/OD would be much nicer.
Seems you're looking for minimal power capability ... why not seek recommendations for a great builder near your city ? ... local ...
Not necessarily a "race" shop ... a good local shop with a solid rep for long-lived builds and complete face-to-face service.
Perhaps you're near Eglin AF Base / Ft Walton Beach / Freeport ? I know the area, But No, I don't have a tip there ... but someone probably does.
Any Warranty issues become quite biased in favor of supplier when dealing with an out-of-state supplier ...
... the buyer has much more clout when the supplier is also subject to same state Court system (i.e. supplier has a physical presence within your state).
I agree, an auto w/OD would be much nicer.
Thread Starter
Burning Brakes
Joined: Nov 2017
Posts: 778
Likes: 112
From: Redneck Riviera, FL
to all that suggested an od trans, i appreciate the thought and i know the advice was given with the best of intentions but i'm committed to using a TH350.
jackson, i wish i could do that but there really isn't anyone in my area (pensacola) that i would feel good about using.
jackson, i wish i could do that but there really isn't anyone in my area (pensacola) that i would feel good about using.
Advanced
Joined: Feb 2013
Posts: 56
Likes: 14
From: Spokane WA
I have a Summit brand turbo 350 in my 1970 Monte Carlo behind a 454 putting out about 450 Hp and over 500 Ft Lbs of torque. It's supposed to be rated for 450 Hp and has held up fine. Be aware that the transmission comes without provision for the passing gear cable, there is a plug blocking off the hole for the cable. Summit states that the transmission is designed to run without it. I don't know why and I never looked in to what parts are missing. The big block has enough torque that I rarely miss it. I will be swapping it out for a turbo 400 due to some horsepower upgrades
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,170
From: Hermosa
I bought a B&M off of amazon for mine. It’s had no problems.
remember you’ll need a new torque converter as well to make the warranty good. Good time to choose a different stall if you want to.
the WOT shift points may need adjustment too, mine shifted way too early out of the box. Or you could swap governor i suppose to keep you current shift points.
part throttle shifts will likely need adjusting as well via an adjustable vacuum actuator if it comes with one, or again you could swap out that part to retain current ones.
remember you’ll need a new torque converter as well to make the warranty good. Good time to choose a different stall if you want to.
the WOT shift points may need adjustment too, mine shifted way too early out of the box. Or you could swap governor i suppose to keep you current shift points.
part throttle shifts will likely need adjusting as well via an adjustable vacuum actuator if it comes with one, or again you could swap out that part to retain current ones.
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Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,114
From: Crossville TN
Any good brand of auto transmission should be able to match your needs for a THM-350 trans. Get a good brand with the best price you can find.
P.S. Make sure the new unit has the CORRECT speedo gearing and overall length (tailshaft housing) that you need before you buy.
P.S. Make sure the new unit has the CORRECT speedo gearing and overall length (tailshaft housing) that you need before you buy.
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
Seems you can buy a rebuilt THM350 Without Converter at your LOCAL Advance Auto Parts for about $1553 outright - $400 core = $1153 exchange
https://shop.advanceautoparts.com/p/...=transmissions
https://shop.advanceautoparts.com/o/...ytransmissions
-addendum-
whatever route you take, make DAMN SURE you have a positive seal on fill tube-case joint!
Since trans runs in petro fluid, Friction disc material is glued on with a WATER-BASED adhesive.
ANY Water that finds its way into the trans will cause trans to shuck its Friction material.
https://shop.advanceautoparts.com/p/...=transmissions
https://shop.advanceautoparts.com/o/...ytransmissions
-addendum-
whatever route you take, make DAMN SURE you have a positive seal on fill tube-case joint!
Since trans runs in petro fluid, Friction disc material is glued on with a WATER-BASED adhesive.
ANY Water that finds its way into the trans will cause trans to shuck its Friction material.
Last edited by jackson; Dec 2, 2019 at 07:20 PM.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,114
From: Crossville TN
The reason to buy one from a QUALITY brand operation is that the general purpose "rebuilders" just tear old units down and throw parts back together with the main goal being to build it cheap and fast.....MORE PROFIT. Quality brands can't get away with that or warranty costs would kill them. I would NEVER buy a rebuilt transmission from an auto parts store. Maybe thru Jeg's or Summit Racing, if it's a branded product with a decent warranty. You've heard Lars' rants about the lousy quality of carb rebuilders' products. The same goes for engines and transmissions. You have to find a reliable source for quality product if you want to have success with replacement products.
Last edited by 7T1vette; Dec 3, 2019 at 01:06 AM.
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
The reason to buy one from a QUALITY brand operation is that the general purpose "rebuilders" just tear old units down and throw parts back together with the main goal being to build it cheap and fast.....MORE PROFIT. Quality brands can't get away with that or warranty costs would kill them. I would NEVER buy a rebuilt transmission from an auto parts store. Maybe thru Jeg's or Summit Racing, if it's a branded product with a decent warranty. You've heard Lars' rants about the lousy quality of carb rebuilders' products. The same goes for engines and transmissions. You have to find a reliable source for quality product if you want to have success with replacement products.
I don't like Interstate (read Inter-Jurisdiction) purchases of Rebuilt/Refurbished/Remanufactured motors or trans (large items). If the seller has No physical presence in buyer's state and If there's a warranty issue that only a Court can settle, any claim has to be made in seller's state Court. Carbs are another kettle of fish: Lars has a very good reputation (if not unique) as trustworthy & engaged rebuilder, tuner & teacher; while carbs are relatively easy to R&R and ship.
That's JMO; I'm only another of CF's herd of cats.
Thread Starter
Burning Brakes
Joined: Nov 2017
Posts: 778
Likes: 112
From: Redneck Riviera, FL
i think the plan will be to get a trans from summit. they're close, have free shipping, and have great customer support and have never given me any crap about returning things. and hope for the best. actually the thing i'm worried most about is finding the right torque converter. off the shelf converters seem to be hit or miss in terms of being a good match for a particular in car application. after 3 attempts with my last project i ended up having one custom built, big $.
thanks guys.
thanks guys.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,114
From: Crossville TN
Whatever brand of trans you buy from Summit, you need to call their tech folks to get the skinny on the best converter for your car & how you want to use it. They will ask info like what amount of torque the engine can produce; what rpm range is the 'power band' on the engine; max rpm; if you will be road racing or drag racing; and if it will be primarily a street vehicle.
With that info, they can recommend a converter with proper power capabilities and a good stall speed to match your needs. This is the right way to do it. Taking advice from some sales desk kid in a local parts store is NOT the right way to do this.
Good luck.
With that info, they can recommend a converter with proper power capabilities and a good stall speed to match your needs. This is the right way to do it. Taking advice from some sales desk kid in a local parts store is NOT the right way to do this.
Good luck.
Thread Starter
Burning Brakes
Joined: Nov 2017
Posts: 778
Likes: 112
From: Redneck Riviera, FL
7t1, unfortunately, i haven't had much luck with recommendations from manufacturers tech reps. with the exception of a well known crate motor the rest of my last project was completely stock. two of the converters were way to loose and one was to tight. i think some of the manufacturers are trying to cover to many applications with one part number, sometimes it works and some times it doesn't. also can be hard to get the seller to except a return on a converter that's been installed. i ended up having one built by Broader Performance in TX. it wasn't perfect but it was very close and i'm happy with it. i'm still hoping to find someone here that has the set up i have and is happy with the converter they installed: base 327/300, th350 and 3.36 diff.
thanks again.
thanks again.