Alright i just picked up an 86 burb but the guy sold it to me mid project for 1500 and he had put a th400 behind the 6.5 not sure the years on either and I’m not sure how to make it work the wiring is a huuuge mess and I honestly feel like it’d be easier to go with a 4911 db2 and I’ve seen a whole book on doing the swap. So my question is is the combo even possible to work? I’ve heard you take out the vacuum pump to do the swap and I need that for the th400. If I can’t do the swap how do I get the electronics to work with the transmission? Thanks for your time and if y’all would like I can post some pictures of the burb
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Th400 behind 6.5
- Thread starter Lucky
- Start date
Will L.
Well-Known Member
Welcome!
Fun rig to have and worth the effort.
Post tons of pics so we see what all you have so we can go from there.
is the 6.5 you have a ds4 electronic injection pump (ip)? Pics and we can tell instant.
YES YES YES db pump instead of ds4. The Bobbie Martin book he posted here on doing the swap doesn’t even apply to yours almost because you already have mechanical pedal, non electronic transmission (which you might reconsider).
you need nothing electronic with that set up. You need nothing vacuum with that set up.
You will need gauges for dash - guessing was the burb original gas?
You will need two batteries wired still for 12volts.
You will need some fuel and a places to go. Haha
build this dude right and you’ll be happy for years with it, providing you build it to match how you’re gonna use it.
which hits the two big questions.
How are you going to use it? Put put grocery getter, tow heavy and often, off road dedicated, or what?
Budget?. How much to get it going if long term build as you drive is the plan...
Fun rig to have and worth the effort.
Post tons of pics so we see what all you have so we can go from there.
is the 6.5 you have a ds4 electronic injection pump (ip)? Pics and we can tell instant.
YES YES YES db pump instead of ds4. The Bobbie Martin book he posted here on doing the swap doesn’t even apply to yours almost because you already have mechanical pedal, non electronic transmission (which you might reconsider).
you need nothing electronic with that set up. You need nothing vacuum with that set up.
You will need gauges for dash - guessing was the burb original gas?
You will need two batteries wired still for 12volts.
You will need some fuel and a places to go. Haha
build this dude right and you’ll be happy for years with it, providing you build it to match how you’re gonna use it.
which hits the two big questions.
How are you going to use it? Put put grocery getter, tow heavy and often, off road dedicated, or what?
Budget?. How much to get it going if long term build as you drive is the plan...
Will L.
Well-Known Member
Oh yeah- fill out signature line with the truck details is best so everyone can knkw what we are dealing with and don’t have to answer same questions over and over.
I know really really bad camera angles but only the face camera works anyways it was a 6.2 before. I have downloaded bobbies book and my plans is a nice daily driver with some jank shit on the trail every once in a while it is dual battery not sure if it’s 1 or 2 thermostat if that matters I’m very new to Detroit’s but reading bobbies book gave me butterflies in my stomach I am excited to make a fun ride out of the burb. Then the butterflies flew away when I started ball parking prices
ak diesel driver
6.5 driver
So is it a th400 or a 4l80e? If it's a th400 not much wiring to do for the tranny and it would be a prime candidate to go db2
ak diesel driver
6.5 driver
If it's a th400 and electronic IP then find a PCM for a manual tranny
Will L.
Well-Known Member
Yeah I would be surprised to see th400 behind that. Those 6.5’s came with 4l80e so he must have picked them up separate if so.
Pic of trans / trans oil pan to be sure.
Did he already put in electric throttle pedal?
Pic of trans / trans oil pan to be sure.
Did he already put in electric throttle pedal?
Will L.
Well-Known Member
No onions on my bigmac!
ak diesel driver
6.5 driver
Depends on whether you want easy or not. Easy would be db2 mechanical IP. Doable would be to find a PCM for a manual transmission and then a wiring diagram.
Will L.
Well-Known Member
Ok cool.
Makes life easy to get it going. You won’t like freeway driving but 0-50 won’t be bad.
What throttle pedal ? If he swapped it to electric already and If he gave you complete harness and the pcm (for a stick shift truck) and pmd you can run the ip you have.
Otherwise best bet is to remove the ip and drop in a new db2. Better choice long term anyways imo.
First get the wiring squared away enough to crank over the engine. Remove all 8 glowplugs and do a compression test. Need to know what is inside and this is what counts. Find out you have dead holes and the rest is wasted time.
Makes life easy to get it going. You won’t like freeway driving but 0-50 won’t be bad.
What throttle pedal ? If he swapped it to electric already and If he gave you complete harness and the pcm (for a stick shift truck) and pmd you can run the ip you have.
Otherwise best bet is to remove the ip and drop in a new db2. Better choice long term anyways imo.
First get the wiring squared away enough to crank over the engine. Remove all 8 glowplugs and do a compression test. Need to know what is inside and this is what counts. Find out you have dead holes and the rest is wasted time.
Will L.
Well-Known Member
So picture of pedal next please
FellowTraveler
Well-Known Member
W/T-400 trans I suspect a diesel governor is needed and the modulator can be switched out for a non-vacuum type, but its been such a long time since I have even seen one.
Sounds like a nice project.
Sounds like a nice project.
JayTheCPA
Well-Known Member
Isn't the advantage of a 4L80e that it locks the TCC where the TH400 does not?
If we want to go in the direction of cool, I'd put the 6 speed in it. This will really wake-up the powertrain. Downside is the expense of a stand-alone controller.
If we want to go in the direction of cool, I'd put the 6 speed in it. This will really wake-up the powertrain. Downside is the expense of a stand-alone controller.
FellowTraveler
Well-Known Member
AND, has overdrive to...
Will L.
Well-Known Member
I would say the big advantage of the 4 l80 is the overdrive 4th gear. Many guys in hmmwvs have the 6.2 with th400. That coupled with the gearing makes doing 60mph a scary event. Here where the major roads have 65 mph speed limits so traffic is usually around 70mph- they just can’t.
When they ride in one with the 4 speed their mouths drop. Then within a year the th400 drops- and a 4 speed goes in. But it’s a descent expense so you have to know you are keeping the rig and gonna use it on the hiway often enough for it. Long term adding the 4 speed isn’t just factoring in fuel savings- which is a lot, think about the engine. If a guy drives 1/2 hour to work on the freeway 5 days a week- that’s a minimum of 10 hours every week that engine is near max rpm. What does that do for the longevity of the engine?
The overheating that has to be fought for this engine- that really is an issue. Higher rpm and this engine puts out way more heat. The front end of his rig with the square body does help in being able to catch more air at high speeds to get out that heat better than a gmt400. Plus when it is radiator time, having a big fat 4 core copper radiator in there helps. But he will still be able to run ak diesel driver’s electroviscous fan clutch system to maximize cooling and mpg. @Lucky - that was a hint for your future fan and fanclutch - you got some reading to do before buying a fan...DONT just buy the stock one.
But my thought is, if the th400 is in there now- I would get it going with it to start. He might start driving the truck and hate old diesels, or maybe all suspension and steering is shot, maybe diffs are shot, and he decides to sell it after driving for just a few months. So I wouldn’t pour a ton of money into it. Yes the vacuum module will need changed but get the engine running first before other stuff, imo.
Stop at local autoparts store and throw in new AC Delco 60G glow plugs. After the compression test. Put a dab of antiseize on the threads before installing.
I missed wether it was originally a diesel truck or not. Wiring in things like a “wait to start” dash light is part of the headache in gas to diesel conversion. Also if gas truck, you will have to drop the fuel tank. You need a 3/8 pickup tube for fuel supply and a 5/16 return fuel line - it is important that it goes down to the bottom of the tank just like the supply one.
IDK if the gas and diesel tank gauge sending units can just be swapped for the added line. Adding a hose inside could be done if the sizing is correct. ONLY use sae30r9 or higher (-r10,-r11) for the rubber fuel line. And if you add hose inside the tank don’t use regular hose clamps. Get the high quality ones like Earl vapor guard because if that clamp comes loose later you will pull out your hair trying to find out what happened.
Leroydiesel.com for the db2 if you go that way. Exactly which db2 takes a little learning so you can know which options will work for ya. The part number is break down
db2831-4927
d is diesel and b is fully mechanical second rendition.
The 2 tells you 2 and plunger pump (there is a 0 that is 4 plunger but thats the exception to the description). You should stay with a 2 plunger pump.
31 is the size of the plungers. Like 29 is 165hp non turbo n/a. 31 is my recommendation for you, middle of the road and easily adjusted up to 250 hp. A 33 is high fuel volume and no one not willing to put on a huge turbo and complete race build the engine should use these.
after the dash- these four tell the accessories like 12v or 24v. With or without tps. Etc.
You should get one with a tps (throttle position sensor). Imo even guys with manual trans should order it with it incase
you choose to use it later for wmi or anything else. It’s like $50 and is way more common parts when needed in the future.
So last 4 number combos that I know would work for you would be 4911*, 5157, 4927,4971,5164. Ones that would also work but are really meant for a bit heavier work truck (15,000 gvw) 4970,5167,4971
*4911- be careful bringing this number up. This became the “secret sauce” pump online for people for some reason- so asking for this one is looking for the most sought after one- even though there are identical ones or better ones- so it is a tip of to some sellers (not Leroy) that they could charge you more and get away with it. Last time I looked around the 4911 was selling new for $450 more than the 5157 which puts out exactly same results.
So which one IF ALL available and same price? 4911 incase you sell it would be more desirable by average joe. But if you are going to keep it forever get the 4927.
( @FellowTraveler ya posted while I am typing- ya got me quick draw!)
All this said about db2 mechanical pump- you have the electronic ds4 now. If he gave you the pcm it is a silver box about 2” size of a piece of paper. And the electric pedal (post picture or look it the pedal has a steel cable attached for db2 or electrical wires for ds4) If you have all that- you could get it running with that and not spend a ton of cash.
You don’t live in Las Vegas do ya? If so I could just swing by and make this easier! haha
When they ride in one with the 4 speed their mouths drop. Then within a year the th400 drops- and a 4 speed goes in. But it’s a descent expense so you have to know you are keeping the rig and gonna use it on the hiway often enough for it. Long term adding the 4 speed isn’t just factoring in fuel savings- which is a lot, think about the engine. If a guy drives 1/2 hour to work on the freeway 5 days a week- that’s a minimum of 10 hours every week that engine is near max rpm. What does that do for the longevity of the engine?
The overheating that has to be fought for this engine- that really is an issue. Higher rpm and this engine puts out way more heat. The front end of his rig with the square body does help in being able to catch more air at high speeds to get out that heat better than a gmt400. Plus when it is radiator time, having a big fat 4 core copper radiator in there helps. But he will still be able to run ak diesel driver’s electroviscous fan clutch system to maximize cooling and mpg. @Lucky - that was a hint for your future fan and fanclutch - you got some reading to do before buying a fan...DONT just buy the stock one.
But my thought is, if the th400 is in there now- I would get it going with it to start. He might start driving the truck and hate old diesels, or maybe all suspension and steering is shot, maybe diffs are shot, and he decides to sell it after driving for just a few months. So I wouldn’t pour a ton of money into it. Yes the vacuum module will need changed but get the engine running first before other stuff, imo.
Stop at local autoparts store and throw in new AC Delco 60G glow plugs. After the compression test. Put a dab of antiseize on the threads before installing.
I missed wether it was originally a diesel truck or not. Wiring in things like a “wait to start” dash light is part of the headache in gas to diesel conversion. Also if gas truck, you will have to drop the fuel tank. You need a 3/8 pickup tube for fuel supply and a 5/16 return fuel line - it is important that it goes down to the bottom of the tank just like the supply one.
IDK if the gas and diesel tank gauge sending units can just be swapped for the added line. Adding a hose inside could be done if the sizing is correct. ONLY use sae30r9 or higher (-r10,-r11) for the rubber fuel line. And if you add hose inside the tank don’t use regular hose clamps. Get the high quality ones like Earl vapor guard because if that clamp comes loose later you will pull out your hair trying to find out what happened.
Leroydiesel.com for the db2 if you go that way. Exactly which db2 takes a little learning so you can know which options will work for ya. The part number is break down
db2831-4927
d is diesel and b is fully mechanical second rendition.
The 2 tells you 2 and plunger pump (there is a 0 that is 4 plunger but thats the exception to the description). You should stay with a 2 plunger pump.
31 is the size of the plungers. Like 29 is 165hp non turbo n/a. 31 is my recommendation for you, middle of the road and easily adjusted up to 250 hp. A 33 is high fuel volume and no one not willing to put on a huge turbo and complete race build the engine should use these.
after the dash- these four tell the accessories like 12v or 24v. With or without tps. Etc.
You should get one with a tps (throttle position sensor). Imo even guys with manual trans should order it with it incase
you choose to use it later for wmi or anything else. It’s like $50 and is way more common parts when needed in the future.
So last 4 number combos that I know would work for you would be 4911*, 5157, 4927,4971,5164. Ones that would also work but are really meant for a bit heavier work truck (15,000 gvw) 4970,5167,4971
*4911- be careful bringing this number up. This became the “secret sauce” pump online for people for some reason- so asking for this one is looking for the most sought after one- even though there are identical ones or better ones- so it is a tip of to some sellers (not Leroy) that they could charge you more and get away with it. Last time I looked around the 4911 was selling new for $450 more than the 5157 which puts out exactly same results.
So which one IF ALL available and same price? 4911 incase you sell it would be more desirable by average joe. But if you are going to keep it forever get the 4927.
( @FellowTraveler ya posted while I am typing- ya got me quick draw!)
All this said about db2 mechanical pump- you have the electronic ds4 now. If he gave you the pcm it is a silver box about 2” size of a piece of paper. And the electric pedal (post picture or look it the pedal has a steel cable attached for db2 or electrical wires for ds4) If you have all that- you could get it running with that and not spend a ton of cash.
You don’t live in Las Vegas do ya? If so I could just swing by and make this easier! haha
I’m in San Diego so I’m a ways out, it was a 6.2 before. I believe it did come with a pcm it’s the box with the three plugs I think. I didn’t see a cable on the pedal. And would it be possible to swap out the the vacuum thing on the transmission with the diesel govener? I’ve heard it’s impossible with the trans installed but not entirely sure. And thanks for the tip on the radiator I just looked at it today during lunch and noticed the transmission lines don’t fit and for me to even have the fittings on the right side the radiator has to be upside down glad it wasn’t me that made that expensive mistake. And I’m looking at some shit on the engine questioning everything like there are some random hoses go everywhere but don’t hook up to anything so I’m slowly coming to the realization that I’ve got to replace even more things lol. Looks like she’s going to be sitting in the parking space of a little while. One of those is the two hoses coming off the power steering I’ve got no idea where those lines go. Like I said absolutely no experience with 6.5s. There’s two other lines that have oil in them that are on the passenger side not sure what those do I think they are for an inter cooler but I don’t think I would have one on the truck since it had a 6.2.
ak diesel driver
6.5 driver
Does your truck have hydroboost? One of the oil lines one the passenger side might be for the turbo
MrMarty51
Well-Known Member
There are electric motor driven vacuum pumps available too.
I know that the 93 Audi my BIL had, it had an electric motor driven vacuum pump on it.
I dont know if the modulator valve on the TH transmissions requires variable vacuum to adjust shift points, if not then that would be an option.
That vac pump on his Audi was a good unit and I believe packed enough vac to function for the brake booster too.
I know that the 93 Audi my BIL had, it had an electric motor driven vacuum pump on it.
I dont know if the modulator valve on the TH transmissions requires variable vacuum to adjust shift points, if not then that would be an option.
That vac pump on his Audi was a good unit and I believe packed enough vac to function for the brake booster too.