What is the weight difference between a 4r70w and a T-45? - TCCoA Forums
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post #1 of 6 (permalink) Old 10-03-2014, 08:26 AM Thread Starter
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What is the weight difference between a 4r70w and a T-45?

Sometime next year I want to swap my well worn, 190,000 mile 95 4.6 and auto trans for an aluminum explorer block/5-speed combo. One of my goals in doing this is to achieve 50/50 weight distribution so I get better handling, as well as reducing wear on my front suspension components. From what I've read here, the explorer block swap is about 100 pounds lighter; what about a T-45 as opposed to a 4r70w? I imagine a manual trans is somewhat lighter just by virtue of not having 2 1/2 gallons of fluid in it.
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post #2 of 6 (permalink) Old 10-03-2014, 09:45 AM
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When I helped my buddy dropp his t45 it was heavy but we didn't need a tranny jack. My transmission on the other hand we did need one. Idk for sure but I would say a good 50 lbs maybe more with fluid and TC.

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post #3 of 6 (permalink) Old 10-03-2014, 10:21 AM
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With converter, the 4R70W will come in around 150-160. A T45 weighs around 110.

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post #4 of 6 (permalink) Old 10-03-2014, 01:47 PM
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Realistically, the weight difference is negligible. Yes you have 3 gallons fewer fluid, and the trans itself is maybe 50lbs lighter, but you have to keep in mind you also have a much heavier flywheel and a clutch and pressure plate which together are notably heavier than just a torque converter. You could get a lightweight flywheel, but on a heavy car like ours, especially one driven on the street, this is going to make it a PITA to drive since you will have to rev the hell out of the engine and slip the clutch like crazy just to get moving from a stop. Plus all the weight of the trans is already towards the center of the car, so any effect on weight distribution is going to be so small it won't be noticable. Don't get me wrong, I am probably the biggest advocate of the T45 swap on this site, and you absolutely should do the conversion, but in terms of weight distribution or reduction, you aren't going to get very far from a T45 swap. On the other hand, it does help handling quite a bit because you can now hold the trans in a particular gear and use engine braking to shift the weight of the car slightly, which will help the car get through the corners.

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post #5 of 6 (permalink) Old 10-03-2014, 01:57 PM
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For the trans itself the weight close to the same dry with a slight advantage towards the T45. My TR3650 seems like it's heavier than the 4R70w, I really struggled getting that thing out of my trunk when I got it and I've manhandled both T45s and 4R70ws in the same exact fashion. The real weight savings is in the converter and fluids, but you also need to account for the weight of the flywheel, clutch assembly, the extra pedal, and whatever bracketry you come up with for the shifter relocation and slave. It'll still end up less than the auto by a fair margin but not as much as you'd think.

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post #6 of 6 (permalink) Old 10-03-2014, 02:38 PM
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Originally Posted by theterminator93 View Post
With converter, the 4R70W will come in around 150-160. A T45 weighs around 110.
Is that dry weight? Add the Mercon V and watch the weight go up 20 lbs. or so.

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