Oh God...is my transmission on its way out?
Grand Champion
Joined: Apr 2010
Posts: 5,011
Likes: 6
From: Meeker, CO
The ugly truth is that the 46R in stock trim is just not well suited to truck duty -- that's why Uncle Chrysler plugged torque management into the microcode. These trucks are just too darn heavy for their transmissions. If you do a lot of city driving so they're constantly shifting through those don't-rattle-grandma's-dentures soft slippery shifts they're not going to last -- that's what killed my factory original at 98,000 miles. If you don't do a lot of city driving but haul heavy loads the clutches will slip, imperceptibly, especially at lower RPM where the line pressure's low, and especially when the unit's cold, and they'll shed material like mad. So if you've got a unit at end of life, and it's in stock trim which was already too weak when it was brand new, there's really not all that much that fiddling the chemicals is going to do for you. It might work for a time in less stressed vehicles, but in this case I wouldn't expect it to be of much use. If you want to toss some Dexron-III in there just for giggles, draw out a quart with one of those cheap ten dollar fluid pumps from the parts store, and dump the Dexron in -- if memory serves your ATF has less than 20,000 miles on it, so it's in fine shape and needn't be changed.
Oh yeah, I meant to mention before about "the grit in the oil helps the clutches stick" BS: Imagine you've got two ends from oil drum barrels, cut off so the sides are about a foot high, and between them you've got a stack of manhole covers holding the barrel ends just barely apart. That's a not-completely-fouled up analogy of a clutch pack in an automatic transmission. Now push down real hard on the top barrel end so that when you twist it, there's no slippage between any mechanical interface and the bottom barrel end turns in perfect unison with the top one. That's an engaged clutch in action. Now take your stack apart and rebuild it with a pound or two of smooth gravel between each manhole cover to simulate loose, circulating friction material, then push down with the same force as before and twist. I can't say I've ever done this, but I'd bet a large sum of real money that the gravel is going to roll between the covers and you're just not going to get that bottom cover spinning as fast as the top one with the same clamping force as before applied.
Anyway, at 160,000+ it's a very reasonable and safe assumption that your transmission is just about done for. I wouldn't do anything to it at all, myself, not even drop the pan for a look. I'd just run it until it acts up, then replace it. Preferably with a Mega Viper, because I'm crazy. If your towing isn't of heavy loads, and you reasonably expect to make the truck someone else's problem before you get another 80,000 after the rebuild, a properly done stock rebuild with an added mild ("heavy duty") shift kit will probably get you that far and then some. Adding a remote filter is always a good idea no matter which way you go -- remote ATF filters are in fact engine oil filters right down to their part numbers, so they come with integral bypass valves that open when the pressure differential (inlet to outlet) becomes excessive. The valves themselves are dirt simple and very unlikely to ever fail, so the risk of plugging up your aux filter with grit to starve your transmission is much greater than the risk of the filter doing it instead. Oh, and for towing with any automatic transmission in any vehicle you want a temperature gauge. Especially in the 46R because the Trans Temp light comes on at a higher temperature than is required to start cooking varnish out of the ATF.
Thread Starter
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Banned Goober Smoocher
Joined: Jun 2010
Posts: 8,916
Likes: 1
I've never tried it. But you're at 160,000+ so it'd be a waste of time and money anyway. MonteC, who's seen a lot of these critters, said that most of them he sees in need of rebuild are somewhere between 140k and 180k miles. Yours is right in the top half of that range where the normal end of service life occurs. Just run it until it punks out on ya, and in the meantime stack your spare nickels for when the big expense is no longer avoidable.
The ugly truth is that the 46R in stock trim is just not well suited to truck duty -- that's why Uncle Chrysler plugged torque management into the microcode. These trucks are just too darn heavy for their transmissions. If you do a lot of city driving so they're constantly shifting through those don't-rattle-grandma's-dentures soft slippery shifts they're not going to last -- that's what killed my factory original at 98,000 miles. If you don't do a lot of city driving but haul heavy loads the clutches will slip, imperceptibly, especially at lower RPM where the line pressure's low, and especially when the unit's cold, and they'll shed material like mad. So if you've got a unit at end of life, and it's in stock trim which was already too weak when it was brand new, there's really not all that much that fiddling the chemicals is going to do for you. It might work for a time in less stressed vehicles, but in this case I wouldn't expect it to be of much use. If you want to toss some Dexron-III in there just for giggles, draw out a quart with one of those cheap ten dollar fluid pumps from the parts store, and dump the Dexron in -- if memory serves your ATF has less than 20,000 miles on it, so it's in fine shape and needn't be changed.
Oh yeah, I meant to mention before about "the grit in the oil helps the clutches stick" BS: Imagine you've got two ends from oil drum barrels, cut off so the sides are about a foot high, and between them you've got a stack of manhole covers holding the barrel ends just barely apart. That's a not-completely-fouled up analogy of a clutch pack in an automatic transmission. Now push down real hard on the top barrel end so that when you twist it, there's no slippage between any mechanical interface and the bottom barrel end turns in perfect unison with the top one. That's an engaged clutch in action. Now take your stack apart and rebuild it with a pound or two of smooth gravel between each manhole cover to simulate loose, circulating friction material, then push down with the same force as before and twist. I can't say I've ever done this, but I'd bet a large sum of real money that the gravel is going to roll between the covers and you're just not going to get that bottom cover spinning as fast as the top one with the same clamping force as before applied.
Anyway, at 160,000+ it's a very reasonable and safe assumption that your transmission is just about done for. I wouldn't do anything to it at all, myself, not even drop the pan for a look. I'd just run it until it acts up, then replace it. Preferably with a Mega Viper, because I'm crazy. If your towing isn't of heavy loads, and you reasonably expect to make the truck someone else's problem before you get another 80,000 after the rebuild, a properly done stock rebuild with an added mild ("heavy duty") shift kit will probably get you that far and then some. Adding a remote filter is always a good idea no matter which way you go -- remote ATF filters are in fact engine oil filters right down to their part numbers, so they come with integral bypass valves that open when the pressure differential (inlet to outlet) becomes excessive. The valves themselves are dirt simple and very unlikely to ever fail, so the risk of plugging up your aux filter with grit to starve your transmission is much greater than the risk of the filter doing it instead. Oh, and for towing with any automatic transmission in any vehicle you want a temperature gauge. Especially in the 46R because the Trans Temp light comes on at a higher temperature than is required to start cooking varnish out of the ATF.
The ugly truth is that the 46R in stock trim is just not well suited to truck duty -- that's why Uncle Chrysler plugged torque management into the microcode. These trucks are just too darn heavy for their transmissions. If you do a lot of city driving so they're constantly shifting through those don't-rattle-grandma's-dentures soft slippery shifts they're not going to last -- that's what killed my factory original at 98,000 miles. If you don't do a lot of city driving but haul heavy loads the clutches will slip, imperceptibly, especially at lower RPM where the line pressure's low, and especially when the unit's cold, and they'll shed material like mad. So if you've got a unit at end of life, and it's in stock trim which was already too weak when it was brand new, there's really not all that much that fiddling the chemicals is going to do for you. It might work for a time in less stressed vehicles, but in this case I wouldn't expect it to be of much use. If you want to toss some Dexron-III in there just for giggles, draw out a quart with one of those cheap ten dollar fluid pumps from the parts store, and dump the Dexron in -- if memory serves your ATF has less than 20,000 miles on it, so it's in fine shape and needn't be changed.
Oh yeah, I meant to mention before about "the grit in the oil helps the clutches stick" BS: Imagine you've got two ends from oil drum barrels, cut off so the sides are about a foot high, and between them you've got a stack of manhole covers holding the barrel ends just barely apart. That's a not-completely-fouled up analogy of a clutch pack in an automatic transmission. Now push down real hard on the top barrel end so that when you twist it, there's no slippage between any mechanical interface and the bottom barrel end turns in perfect unison with the top one. That's an engaged clutch in action. Now take your stack apart and rebuild it with a pound or two of smooth gravel between each manhole cover to simulate loose, circulating friction material, then push down with the same force as before and twist. I can't say I've ever done this, but I'd bet a large sum of real money that the gravel is going to roll between the covers and you're just not going to get that bottom cover spinning as fast as the top one with the same clamping force as before applied.
Anyway, at 160,000+ it's a very reasonable and safe assumption that your transmission is just about done for. I wouldn't do anything to it at all, myself, not even drop the pan for a look. I'd just run it until it acts up, then replace it. Preferably with a Mega Viper, because I'm crazy. If your towing isn't of heavy loads, and you reasonably expect to make the truck someone else's problem before you get another 80,000 after the rebuild, a properly done stock rebuild with an added mild ("heavy duty") shift kit will probably get you that far and then some. Adding a remote filter is always a good idea no matter which way you go -- remote ATF filters are in fact engine oil filters right down to their part numbers, so they come with integral bypass valves that open when the pressure differential (inlet to outlet) becomes excessive. The valves themselves are dirt simple and very unlikely to ever fail, so the risk of plugging up your aux filter with grit to starve your transmission is much greater than the risk of the filter doing it instead. Oh, and for towing with any automatic transmission in any vehicle you want a temperature gauge. Especially in the 46R because the Trans Temp light comes on at a higher temperature than is required to start cooking varnish out of the ATF.
I guess that's all I can do I suppose. Then when it gets closer to replacement time start buying that stuff.
And as far as replacing the truck, hell no. This truck will stay with me until it's absolutely necessary for it to go. Though I might be dead first. lol
Record Breaker
Joined: Dec 2008
Posts: 1,585
Likes: 0
Not just to be contrary:
It doesn't work that way. That's one of the widely known logical fallacies, expressed in Latin as post hoc, ergo propter hoc -- it happened after, so was caused by. In reality, you had to rebuild because those transmissions were shot. It often happens that guys get freaked out over that expensive transmission that's been shifting poorly for a while and slipping perceptibly recently and hope for a miracle by way of fluid change and band adjustment. Then when they don't get it, they attribute the absence of a miracle to the work they just did.
Friction material circulating in the oil causes wear of close tolerance parts, so your transmission develops internal leaks that reduce pressures and cause additional slippage, which causes additional friction material wear, and down the spiral waterfall you go in a vicious circle.
It doesn't work that way. That's one of the widely known logical fallacies, expressed in Latin as post hoc, ergo propter hoc -- it happened after, so was caused by. In reality, you had to rebuild because those transmissions were shot. It often happens that guys get freaked out over that expensive transmission that's been shifting poorly for a while and slipping perceptibly recently and hope for a miracle by way of fluid change and band adjustment. Then when they don't get it, they attribute the absence of a miracle to the work they just did.
Friction material circulating in the oil causes wear of close tolerance parts, so your transmission develops internal leaks that reduce pressures and cause additional slippage, which causes additional friction material wear, and down the spiral waterfall you go in a vicious circle.
Champion
Joined: Oct 2009
Posts: 4,717
Likes: 10
From: N/A
^^^ Tell you this if you leave it you might need a new trany or you can try to save it by changing the oil, let's see maybe $30 in oil and filter or $2500 for a trany take your pick. What's your Dad say???? What's the trany shop say? This would be like oh I have water in my gear oil so I will just leave it and see what happens NOT a good plan.
Champion
Joined: Oct 2009
Posts: 4,717
Likes: 10
From: N/A
