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Lockup trans swap
- Thread starter tgee
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I just got done doing mine. Way better unit and TC lockup is great. I have the parts list if needed.
Is it a 2x4 or 4x4 you are looking at converting?
Is it a 2x4 or 4x4 you are looking at converting?
All the parts are available thru Cummins so if you have a local dealer you should be good. All the parts listed are sourced from a 95 2x4 2500 with a diesel.
3990139 - Engine adapter
3946161 - Flex plate
3604684NW - Reman Starter
I ended up getting a new starter thru a local rebuilder/reseller instead of the reman.
On a 2x4 the upgrade is relatively easy. Everything will fit with a few modifications. The engine adapter sets the trans back 1. 25" to account for the lockup TC. You need to redrill the holes for the frame portion of the shift linkage mount. I redrilled the holes for the cross member mount instead of modifying the trans mount. That was going to take some ingenuity to retain the stock mount and stock postion of the cross member.
I did not have to cut down the drive shaft, yet. By moving the center support as far back as the holes allow I still had better than an inch play in the slip yoke so polished the yoke up back to the base so the dust seal will make a good seal. Still had 2" or a little better play in the rear portion of the drive shaft and considering the angle it should not use that up in suspension travel.
The frame will have to be ground back about 1/4 inch where the starter sits. The newer style starter tips out more and will hit the the top of the frame rail. A 4" grinder will fit up there without the starter installed and you can grind it back for enough clearance.
The first thing I noticed is the stock converter has better torque multiplication and stall speed. The lockup engages firmly and brings the rpm's down nicely at cruise. I bought the trans used from Cherry Auto and so far it is working well.
With the weight your friend is towing I would highly reccomend a multi-disk converter and a VB upgrade.
Right now I am using a mystery switch for TC lockup but there are several controllers available that would do the job. To do it really cheap a vaccum switch to break the circuit at idle would work, however, you would still need to manually shut the lockup off in city driving.
PM me if you need anything or just post here. Good luck.
3990139 - Engine adapter
3946161 - Flex plate
3604684NW - Reman Starter
I ended up getting a new starter thru a local rebuilder/reseller instead of the reman.
On a 2x4 the upgrade is relatively easy. Everything will fit with a few modifications. The engine adapter sets the trans back 1. 25" to account for the lockup TC. You need to redrill the holes for the frame portion of the shift linkage mount. I redrilled the holes for the cross member mount instead of modifying the trans mount. That was going to take some ingenuity to retain the stock mount and stock postion of the cross member.
I did not have to cut down the drive shaft, yet. By moving the center support as far back as the holes allow I still had better than an inch play in the slip yoke so polished the yoke up back to the base so the dust seal will make a good seal. Still had 2" or a little better play in the rear portion of the drive shaft and considering the angle it should not use that up in suspension travel.
The frame will have to be ground back about 1/4 inch where the starter sits. The newer style starter tips out more and will hit the the top of the frame rail. A 4" grinder will fit up there without the starter installed and you can grind it back for enough clearance.
The first thing I noticed is the stock converter has better torque multiplication and stall speed. The lockup engages firmly and brings the rpm's down nicely at cruise. I bought the trans used from Cherry Auto and so far it is working well.
With the weight your friend is towing I would highly reccomend a multi-disk converter and a VB upgrade.
Right now I am using a mystery switch for TC lockup but there are several controllers available that would do the job. To do it really cheap a vaccum switch to break the circuit at idle would work, however, you would still need to manually shut the lockup off in city driving.
PM me if you need anything or just post here. Good luck.
I was wondering, could you plumb a hobbs switch into the hydraulic port for the OD clutch? If so then you could have the TC clutch apply when it the trans hit 4th, then when it comes out of 4th (slowing down or kickdown) it would break the circiut for the lockup solenoid..... Think it would work?
I have been kicking around ideas about how to activate/deactivate with a pressure switch also. To begin with I am not sure there is a port to tap for the OD clutch apply pressure. Then there is the problem of what pressure to set it for because the line pressure will vary depending on rpm's and shift point. Finally, I don't think you want the TC locking up at the same time the OD clutch applies and haven't figured out how to delay that enough to make it usable. Every thing so far tells me "buy a controller" but am still looking at the schematics and researching.
You are correct, just got thru looking at my FSM and there appears to be no pressure port for O/D... . BUT, further investigation revealed (lemme know if I`m WAAYYY out in left field here)that, you could make it work using two hobbs switches. See link at bottom for element in use chart. Put one switch that is closed under pressure on the port for the front clutch, this will allow lock up in 3rd/4th AND reverse(we don`t want reverse do we?LOL). In series in the same ckt your building put another hobbs, but this one goes open under pressure, place this switch on the pressure port for the rear servo, this should kill the L/U solnoid when the trans is in rev. You would have to play with psi specs for the switches (rev is 300 psi) and you might need to insert an orifice in the hobbs on the front clutch to help with timing it, but i think it might work. Now all i need is a lock up trans in my truck... LOL.cerberusiam said:
https://www.turbodieselregister.com/user_gallery/displayimage.php?&photoid=18612&width=0
Yep, that would work and I considered the same approach. How about coasting up to a stop light/sign? Trans is still in drive until enough load is put on to downshift. No load, no downshift and the TC is still locked unless the load of a locked converter will be ebough to cause a down shift. An electrial switch to open when the brake is applied would work but if you feather the throttle you could concievably start out in drive depending on your VB and TV cable setup. Tapping the VSS and only allowing lockup over a certain speed would work but not sure what kind of signal one would have to work with.
The other scenario that worries me even worse is the shift into drive under a load and the TC locks. A stock trans does not allow lockup under load for a reason. The shafts will not take the torque unless there is some slippage. Talking to people who have snapped input shafts indicates its not the WOT shifts that are a problem but part throttle on/off throttle daily driving that could be a killer. When the TC is locked and you snap the throttle back and forth in the torque band it definitely causes severe motion changes.
Let me ask, "Am I way out in left field"?
More thoughts from the dark side.
The other scenario that worries me even worse is the shift into drive under a load and the TC locks. A stock trans does not allow lockup under load for a reason. The shafts will not take the torque unless there is some slippage. Talking to people who have snapped input shafts indicates its not the WOT shifts that are a problem but part throttle on/off throttle daily driving that could be a killer. When the TC is locked and you snap the throttle back and forth in the torque band it definitely causes severe motion changes.
Let me ask, "Am I way out in left field"?
More thoughts from the dark side.
Crank Pilot Bushing
Did you have any problems with pilot bushing not being the correct size. I am getting ready to do the swap on 4x4 and was curious called dealer they listed a different part #s for ' 91 and the '95 transmission I have? Before you buy a new adapter plate for $200 place ad in TDR classifieds I bought mine for $100 If you need a few names let me know zgramling@yahoo
Did you have any problems with pilot bushing not being the correct size. I am getting ready to do the swap on 4x4 and was curious called dealer they listed a different part #s for ' 91 and the '95 transmission I have? Before you buy a new adapter plate for $200 place ad in TDR classifieds I bought mine for $100 If you need a few names let me know zgramling@yahoo
618 has lock-up
A 618 is a lock-up transmission if you are talking about a 518 you would still need a new starter, lock-up convertor, 618 style adapter plate (so the lock-up convertor will fit), new style shaft and valve body. and you would still have the weaker 518 with less clutches in over-drive along with all the other weaker parts including the case that is not as strong and sprags with less gears dollar for dollar?
And what was I thinking about a pilot bushing? Must have a 4500 dancing in my head ( automatic- transmission no pilot bushing, stick- pilot bushing)
HERE IS A PROCESS MY transmission GUY GAVE ME HOPE IT HELPS!
no L/U to 618 with L/U
Yes, we did it to his own truck. He is on his way back from Mexico, and should be here on Sunday.
It is a lot of trouble, but I guess it could have been worse.
We changed the case, pump (I think), valve body with solenoids, and converter of course. I’ll have to check with Jim to make sure on the trans parts changed, but I think that was it. You also need the three pin case connector and vehicle wiring harness.
That is the simple part.
He wired lockup to an old style floor mounted dimmer switch on the floor. He had a shift kit in it from Tony Garcin that allowed lockup in any gear, also.
That was also pretty simple.
The pains come upon installation.
The aluminum block adapter is deeper on lockup transmissions, so you are going to need one of those. The starter that mounts to it is different also, so you need the newer style one of those. We swapped flexplates. They looked the same, but I think there was some minute difference around the pilot area.
This of course moves the whole transmission and transfer case back maybe an inch and a half.
We had the front driveline lengthened, and the rear shortened.
Jim welded an extra piece to the shift linkage pivot to extend it farther back. It isn’t perfect, because it is on an angle, but it was close enough for Jeff. <G> The throttle linkage was left alone, because it is a cable and moving the transmission didn’t make a difference.
The front cooler line had a rubber piece in it, so we were able to attach that without modification, and the rear we had to bend a little bit to get it to reach. <BG>
It had the old style crossmember which uses six hundred bolts to attach it to the frame. Jim decided to weld another steel plate to the plate that bolts to the three bolt cast iron transmission mount adapter and cut some slots in it to allow the two big mount bolts to slide through it. You can just barely beat a socket on to the nuts to run them in with an impact.
The only other problem, or modification, that I can think of was the transfer case linkage. It has a 205. The shifter bracket that bolts to the side of the overdrive unit was spaced out with longer bolts and two 7/16” or 1/2” nuts between the bracket and case on each bolt. The floor may need to be notched to get the last position in the transfer case, also. We didn’t have to, but it is close. I noticed the bracket has another slot for the linkage to go into, perhaps for another application, which would have spaced it out probably the correct distance. It was easier to do it the way we did it, though.
This next part may be of special significance if you are seriously considering this. It may be something that could develop some discussion, also.
I haven’t driven his truck, so I can not tell you the specifics, but Jim and Jeff have both experienced this. At certain RPMs, in lockup only, there is a pretty noticeable vibration cruising down the road. It is a harmonic type of vibration. If he hits the lockup switch, the TCC comes off, and the vibration is gone. From their description, this vibration is rather intense. Jeff and Jim have different opinions on what the problem is. Since the vibration is only there with the converter clutch engaged, Jim thinks it may be transmitting vibration from the diesel throughout the truck. He also pointed out that the mount system on the older non lockup trucks is completely different from the newer body style lockup ones, which may contribute to transferring the vibration to the rest of the truck.
I don’t think this vibration is very comfortable, so it may not be something your customer would like to endure. Jeff and Jim can probably add more detail to this later.
Taylor
A 618 is a lock-up transmission if you are talking about a 518 you would still need a new starter, lock-up convertor, 618 style adapter plate (so the lock-up convertor will fit), new style shaft and valve body. and you would still have the weaker 518 with less clutches in over-drive along with all the other weaker parts including the case that is not as strong and sprags with less gears dollar for dollar?
And what was I thinking about a pilot bushing? Must have a 4500 dancing in my head ( automatic- transmission no pilot bushing, stick- pilot bushing)
HERE IS A PROCESS MY transmission GUY GAVE ME HOPE IT HELPS!
no L/U to 618 with L/U
Yes, we did it to his own truck. He is on his way back from Mexico, and should be here on Sunday.
It is a lot of trouble, but I guess it could have been worse.
We changed the case, pump (I think), valve body with solenoids, and converter of course. I’ll have to check with Jim to make sure on the trans parts changed, but I think that was it. You also need the three pin case connector and vehicle wiring harness.
That is the simple part.
He wired lockup to an old style floor mounted dimmer switch on the floor. He had a shift kit in it from Tony Garcin that allowed lockup in any gear, also.
That was also pretty simple.
The pains come upon installation.
The aluminum block adapter is deeper on lockup transmissions, so you are going to need one of those. The starter that mounts to it is different also, so you need the newer style one of those. We swapped flexplates. They looked the same, but I think there was some minute difference around the pilot area.
This of course moves the whole transmission and transfer case back maybe an inch and a half.
We had the front driveline lengthened, and the rear shortened.
Jim welded an extra piece to the shift linkage pivot to extend it farther back. It isn’t perfect, because it is on an angle, but it was close enough for Jeff. <G> The throttle linkage was left alone, because it is a cable and moving the transmission didn’t make a difference.
The front cooler line had a rubber piece in it, so we were able to attach that without modification, and the rear we had to bend a little bit to get it to reach. <BG>
It had the old style crossmember which uses six hundred bolts to attach it to the frame. Jim decided to weld another steel plate to the plate that bolts to the three bolt cast iron transmission mount adapter and cut some slots in it to allow the two big mount bolts to slide through it. You can just barely beat a socket on to the nuts to run them in with an impact.
The only other problem, or modification, that I can think of was the transfer case linkage. It has a 205. The shifter bracket that bolts to the side of the overdrive unit was spaced out with longer bolts and two 7/16” or 1/2” nuts between the bracket and case on each bolt. The floor may need to be notched to get the last position in the transfer case, also. We didn’t have to, but it is close. I noticed the bracket has another slot for the linkage to go into, perhaps for another application, which would have spaced it out probably the correct distance. It was easier to do it the way we did it, though.
This next part may be of special significance if you are seriously considering this. It may be something that could develop some discussion, also.
I haven’t driven his truck, so I can not tell you the specifics, but Jim and Jeff have both experienced this. At certain RPMs, in lockup only, there is a pretty noticeable vibration cruising down the road. It is a harmonic type of vibration. If he hits the lockup switch, the TCC comes off, and the vibration is gone. From their description, this vibration is rather intense. Jeff and Jim have different opinions on what the problem is. Since the vibration is only there with the converter clutch engaged, Jim thinks it may be transmitting vibration from the diesel throughout the truck. He also pointed out that the mount system on the older non lockup trucks is completely different from the newer body style lockup ones, which may contribute to transferring the vibration to the rest of the truck.
I don’t think this vibration is very comfortable, so it may not be something your customer would like to endure. Jeff and Jim can probably add more detail to this later.
Taylor
convertor shudder
By the way transmission gut said the shudder in lock-up is very well possible the cause of a cheap convertor with no dampeners in it. So don't let theshudder problem scare you. He sold me a pro torque brand that has vibration dampeners in it. This is the brand many of the monster truck driers use along with other race drivers it is a custom built convertor that is made for many of the companies we see such as BD, possibly DTT, and ATS what companies buy it for sure I don't know so don't hold me to it. The good thing is he buys them direct and is a couple hundred cheaper than the other guys.
By the way transmission gut said the shudder in lock-up is very well possible the cause of a cheap convertor with no dampeners in it. So don't let theshudder problem scare you. He sold me a pro torque brand that has vibration dampeners in it. This is the brand many of the monster truck driers use along with other race drivers it is a custom built convertor that is made for many of the companies we see such as BD, possibly DTT, and ATS what companies buy it for sure I don't know so don't hold me to it. The good thing is he buys them direct and is a couple hundred cheaper than the other guys.
I paid $650. 00 for my pro torque not too bad for the quality they are supposed to have
Yep on the 518 to 618 conversion. New pump, stator support, input shaft, and VB and it will work. The parts all interchange. However, as was stated earlier you have the weaker case, parts, clutches, etc. with the 518. If you are rebuilding from scratch then its not so bad as you can drop all the newer stuff into the older case with a few exceptions.
Thats interesting on the vibration in lockup mode. Mine actually smoothes out and quiets down at road speeds in lockup. I have some noise and vibe about 35 mph but injectors are so bad not sure problem is with engine or trans.
Thats interesting on the vibration in lockup mode. Mine actually smoothes out and quiets down at road speeds in lockup. I have some noise and vibe about 35 mph but injectors are so bad not sure problem is with engine or trans.
You can use a 47RE also if you want to go the extra expense of a VB and controller. In some cases that would be preferable as the RE has more clutches in critical places and will take more power and loads when pulling. The RH models are starting to get a little scarce so RE are easier to find.
One more thing on lockup control. I wonder if either of these products would work?
B&M Lockup controller for mech speedo
or this
B&M Lockup controller for elec speedo
Granted they are for GM products, but it would prob work with some fabrication... and it`s pretty cheep
#ad
Here`s B&M`s pdf page on it, scroll down about 1/2 way.
B&M Lockup controller for mech speedo
or this
B&M Lockup controller for elec speedo
Granted they are for GM products, but it would prob work with some fabrication... and it`s pretty cheep
#adHere`s B&M`s pdf page on it, scroll down about 1/2 way.
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FREE!
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Subscribe
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Back Issues
Subscription Status
Address Change Form
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Ram Diagnostic Trouble Codes
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