#2711, "RE: Final Drive??!!?" In response to Reply # 2
And read the topic pinned above called "Read this before asking anything!". In it you will find all the info you need to get started. Opinions on the mod can be found by searching the A/T section for "final drive".
Corbin
'95 ESI-T HRC+FMIC+ETC...
Gimme fuel...Gimme fire...Gimme that which I desire
#2766, "RE: Final Drive??!!?" In response to Reply # 3
what exactly does it do? I've tried searching, but all i can find is that, "its a good mod".. does it change JUST your final gear? i really dont understand what makes this a good mod. B/c in the 1/4.. we wont even reach our final gear.. so wouldn;t this mod be pointless? Please help.. and sorry for asking a nooby question
#2770, "RE: Final Drive??!!?" In response to Reply # 5
well you are only replacing the "final gear" right? So how does that increase acceleration if you are only changing your final one.. and not the other 3 gears?
#2771, "RE: Final Drive??!!?" In response to Reply # 6
NO you are not replacing a "gear" of the transmission as in 1 2 3 4.
You are replacing the FINAL DRIVE or the final set of GEARS, not to be confused with clutch packs that are "gears" of the trans among other things. This FINAL DRIVE is the last rotation before another shaft that spins energy towards the axle, anyone feel free to correct me if i'm wrong. It's been a while since ive touched or cared for an A60 .
By changing the FINAL DRIVE ratio, are you with me?, you increase or decrease acceleration. Just like any sort of gear set, if you have equal amount of teeth on each gear it will spin equally {duh}. If you have a different amount on one teeth from the other, the spun or spinning gear will turn faster or slower depending on the number ratio.
Now I havnt counted the teeth on the stock or FINAL DRIVE GEARS but people are doing the mod and increasing acceleration so i'd say it's a good ratio to have. Much better than stock anyway.
Go to howthingswork.com or howstuffworks.com whatever it is, either one will take you to where im talking about, and learn about gears and gear ratios. It will help you out a lot in your auto journey. Also go read up on how AT transmission work, that will also help with the knowledge you need to know about an automatic.
Joseph
PS - I repeat, you are not changing any "final gears" in your transmissions such as 4th gear. I am only saying this because you said "we dont even reach our 'final gear' at the track". I assume you meant 4th gear. The FINAL DRIVE GEARs are at a constant spin if you are moving.
#2775, "RE: Final Drive??!!?" In response to Reply # 8
dude, guys.. you are all sooooo beautiful.. i have tried searcing in this forum for it.. and also in dsmtuners.com.. but i didn;t find too much about it. Thank you so much. i'm still a little confused.. but i am better off than before.
#2776, "RE: Final Drive??!!?" In response to Reply # 9
Look man here is what we'll call the "Energy Transfer Path". Otherwise known as using the engine and transmission to move forward or backwards.
Engine>Torque Converter>Internal Gearing of Transmission>Final Drive Gears(at the second final drive gear power going to the pass. side is now turned towards the back of the car and towards the diff)>Transfer Shaft towards the diff>diff>axles>wheels.
Basically the final drive gears take the energy going from the actual gear process gives them a u-turn so that you can drive the car forward or backwards. IM me if you'd like me to explain it better. But it is pretty simple. Just dont let the word "gears" confuse you anymore.
#2778, "RE: Final Drive??!!?" In response to Reply # 11
well techniccally the last gear is the side gear inside the ring gear, and the transfer gears are actually upstream of the whole ring and pinion to begin with, but its all good.
background:
rwd transmission power flows through one basic shaft, more or less, in the front and out the back in a straight line. because fwd cars usually use transverse engine arrangements and transmission width has to be curtailed, what would be the tailshaft housing of a RWD transmission is replaced by a set of gears that translate the power downward to another shaft that drives the ring and pinion. that set of gears is the one being replaced in this mod.
luckily, since chrysler used the 604 on a wide variety cars with hugely varying weights and powerbands, they decided to vary the ratio of the transfer gear set to make cheap and easy gearing changes. the set with the best ratio for acceleration is what people are using and calling the 'final drive mod' tho theoretically you could use any of the different ratios and get an effective differential ratio of 3.17:1 all the way up to 4.17:1 or whatever it is the shortest gears come out to.
the reason people call it a final drive mod because it modifys the 'final drive ratio' of the transmission, which is also called by several different things but actually refers to the total ratio of all the gear sets from axle to tire in top gear. with the gears discussed here that comes out to something like 2.9:1 as opposed to stock which i believe is 2.69:1. you get the final drive ratio by taking the differential ratio and multiplying it by the top gear ratio, which in this case is .69:1, or the other way around by dividing. that name is accurate in that the gears change the final drive ratio, but inaccurate in that people really only do this mod to affect the performance of the 1st three gears, not 4th, lol.
i personally call it the 'transfer gear mod', because it makes more sense to me. hope that was in any way useful. 1993 Dodge Dynasty LE 3.3 Auto, 95k, Stock. 16.2@84mph
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