Engine and drivetrain swap - RD28T to TD42

Mates after two rounds of head problems on my RD28T, I've found a guy with a TD42 donor car (TD42 with ZD30 drivetrain) who is willing to do a complete swap for me - engine, transmission and rear axle and anything else needed. I've read through the forums here and have an idea about what is required to modify the RD chassis to fit the new setup, but I have some questions about the TD42 in general.

The TD42 is a 1995 silver top n/a with about 180000km on it. He himself has put about 40k on the engine. What do I need to look for with the TD? Are there any problems that would show up with that kind of kms on the engine?

I know these are legendary for reliability, I just want to make sure I am doing the right thing before dropping that kind of cash.

Hey mate, guessing the old 2.8 is not so good then.

I'd do a compression test and hook up an oil pressure Guage if possible. Also a cold start should show up the condition pretty well and look under the oil cap for any sludge it should nice & clean. Nice low Ks tho sounds good.

Thanks, mate. Working to get a compression test done soon. The guy I would get it from ran it for a while in his own Patrol (40k kms) without any problems, but ran into registration problems with the truck and can no longer legally drive his rig - that's why he is offering to pull it from his and put it in mine.

The 2.8 went through a full rebuild about a year ago and ran beautifully after that until now. I'm guessing our extreme temps played a number on the engine, and in a less extreme climate, I think it would be a fine engine to have. Dealing with our extreme weather here, I need the most reliable engine I can have. Breaking down on an ice road in the middle of the taiga isn't really an option ;)

Another update on the TD - the guy who offered it said it starts with 1/2 a crank in summer and winter at -40C as long as there is fuel and battery power. Have set it up with my mechanic to do a compression test and full diagnostics on Monday. We'll see what the results of that will be and then proceed from there.

the main issues with the TD42 are..............

a barely adequate cooling system, rarely able to keep it cool in really hot conditions

make sure you get the water pump and thermostat checked for operating properly - new belts, and a thorough clean out of the radiator

an N/A (Naturally Aspirated) TD42, dont let the EGT's get over 450* - a Turbo one - never over 550*



PS - what happened to the RD??? what did I miss????

your gear box should be the same, just the bell housing is different

you should get 4.11 or 3.9 gears for the diff - (speedo accurate with 4.11 - but better take off and off road with 3.9's just low top speed)

- or is it the other way around - cannot remember now

Would the radiator from my RD be adequate or do I need a different one? Luckily our weather here is more severe cold than severe heat. We will get up to 30C or maybe a bit higher but that will only last for a couple of weeks max.

A 1995 N/A silver top is the engine I would be putting in. My RD developed a head problem back in December after coming back from a trip on the winter ice road. Started getting a knock, vibration and smoke and loss of power. Mechanic said injectors so I replaced them and nothing changed. Seems to be in the head - either a spring, valve or lifter somewhere, and I've also developed a head gasket leak around the #1-3 cylinders. All of this is after I just had a full engine rebuild 1 year ago. Have only put maybe 10k Kms on the rebuild.


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Quote:

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Originally Posted by Bigcol

your gear box should be the same, just the bell housing is different

you should get 4.11 or 3.9 gears for the diff - (speedo accurate with 4.11 - but better take off and off road with 3.9's just low top speed)

- or is it the other way around - cannot remember now

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I will do the full swap with the gearbox and rear diff off the donor car. I'm running 33s so the standard diff from the TD is 4.11 I believe so it should work well. Anything else I'm overlooking?


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Another thing that I just thought of, which isn't a big deal, but something else to consider. I would be going from a turbo engine to a N/A 4.2, meaning I no longer need my boost gauge. I have an EGT gauge paired with it, but I'd need another gauge to throw in beside it. What other gauge would I need with the 4.2 N/A? Oil pressure? Need something to fill the hole ;)

Ok, in the process of having the diagnostics run on the 4.2 I am considering swapping in. Here are the numbers:

Compression
1 = 25 bar / 362.59 psi
2 = 27 bar / 391.6 psi
3 = 29 bar / 420.6 psi
4 = 29 bar / 420.6 psi
5 = 23 bar / 333.59 psi
6 = 25 bar / 362.59 psi

According to the manual, the compression should be 29.4 bar / 427 psi with a minimum of 24.5 bar / 356 psi and a difference of 2.9 bar / 43 psi between cylinders. That makes cylinders 1&6 on the low end, but within reason but 5 is lower than the minimum. The guy has never regulated or adjusted the tappets/valves and lifters, so that could adjust the numbers slightly higher on the low cylinders.

It cranks perfectly when hot and supposedly cranks well in the cold, but obviously by the time it got to the shop it was hot, so hard to test that one. Mechanic pulled the dipstick and checked for exhaust back pressure to see if the pistons were excessively worn. It had a little exhaust gas come out, but nothing serious he said - acceptable and average for the age and kms on the engine.

I would like some input from the gurus here with the TD42. Is it worth dropping in this engine with the compression readings that I posted? Or am I asking for more trouble later on down the road in the form of a rebuild if I put this one in? Asking for advice here.

Quote:

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Originally Posted by Bigcol

your gear box should be the same, just the bell housing is different

you should get 4.11 or 3.9 gears for the diff - (speedo accurate with 4.11 - but better take off and off road with 3.9's just low top
- or is it the other way around - cannot remember now

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Gearbox is totally different on td42 to rd28. Transfer cases are the same but diffent adapter housing

Gearbox would be swapped out as well

there you go, I was told they were the same

I didnt know.....................

Anyone have any input on the compression readings I posted earlier? Is the engine worth it or am I looking at a dud?


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Hey mate, yeah bugger hoping it would have checked out pretty well with low Ks and sounds like it runs & starts beutiful. Is it worth doing a another test know sometimes they can be a bit temperamental?

Hey mate, assuming the engine was hot when you did the test?


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Yes. The engine was hot when the test was done - it had just been driven over to the shop. I'm having him go back today and get the valves and lifters adjusted today and then will retest the compression to see if it makes any difference.


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180k is nothing in AUS speak some here have
motors with 500k on them and still going strong

I'm not worried about the Ks on it. I'm a bit more concerned about the low compression readings. When I bought my RD I had one cylinder with a very low reading and it wound up costing me a complete rebuild within the year. Just want to make sure I don't make the same mistake with this engine.


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Quote:

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Originally Posted by AB

Hey mate, assuming the engine was hot when you did the test?


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Yes it was hot/warm. Wasn't it supposed to be?


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I think the compression readings are OK, and I think they will be better with valve adjustment too.

My opinion is to go for it, and your mechanic will most probably offer his advice too, but the TD42 is fairly bulletproof, and the old Silver-tops were the pick of the NA Version too.

Thanks mate for the input. I'm having the mechanic adjust the valves today and then retest, so I'll update on the findings when I get the new readings.

Quote:

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Originally Posted by SiberianPatrol

Yes it was hot/warm. Wasn't it supposed to be?


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Yes mate supposed to be warm/hot. Just checking that's all.


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Quote:

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Originally Posted by SiberianPatrol

Ok, in the process of having the diagnostics run on the 4.2 I am considering swapping in. Here are the numbers:

Compression
1 = 25 bar / 362.59 psi
2 = 27 bar / 391.6 psi
3 = 29 bar / 420.6 psi
4 = 29 bar / 420.6 psi
5 = 23 bar / 333.59 psi
6 = 25 bar / 362.59 psi

According to the manual, the compression should be 29.4 bar / 427 psi with a minimum of 24.5 bar / 356 psi and a difference of 2.9 bar / 43 psi between cylinders. That makes cylinders 1&6 on the low end, but within reason but 5 is lower than the minimum. The guy has never regulated or adjusted the tappets/valves and lifters, so that could adjust the numbers slightly higher on the low cylinders.

It cranks perfectly when hot and supposedly cranks well in the cold, but obviously by the time it got to the shop it was hot, so hard to test that one. Mechanic pulled the dipstick and checked for exhaust back pressure to see if the pistons were excessively worn. It had a little exhaust gas come out, but nothing serious he said - acceptable and average for the age and kms on the engine.

I would like some input from the gurus here with the TD42. Is it worth dropping in this engine with the compression readings that I posted? Or am I asking for more trouble later on down the road in the form of a rebuild if I put this one in? Asking for advice here.

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Hmm it doesnt look good. You have a couple in the lower end of the spec not to mention you are well out on the max spec of variance across cylinders. Hopefully the valve adjustment sees some gain otherwise leave it alone. You could also ask the mech to do a leak down test.

Quote:

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Originally Posted by nissannewby

Hmm it doesnt look good. You have a couple in the lower end of the spec not to mention you are well out on the max spec of variance across cylinders. Hopefully the valve adjustment sees some gain otherwise leave it alone. You could also ask the mech to do a leak down test.

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He just sent these results. Test done on a cold engine after adjusting the valves and lifters. He is warming the engine up now and will retest when up to operating temp

1-24,5
2-24,5
3-24
4-24,5
5-24
6-25

Looks more promising but will wait for the warm engine results.


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Numbers dropped off when the engine was warmed up. Compression dropped to 23 in some cylinders. Mechanic did a wet test and the promptly rose, thus indicating at a minimum a piston ring problem. Will try to negotiate the price down with the seller, but if he won't budge on the price, this one is a no-go for me.


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Bugger mate, sounded promising. Very rare to get a silver top with that low K's over here, would of thought it checked out really well.

Yeah it sounded like a good offer, but I can't ignore the diagnostic results. If I can get it cheap, I may still buy it and overhaul it, then drop it in.

Bummer Mike how scarce are the 4.2s over there?

4.2s can be found, because there are a lot of swaps from the ZD30. Almost every Patrol you see with a 4.2 is a swap. Very rare to find one with a factory 4.2.

It honestly doesn't matter too much where you buy a used TD from. More than likely you will have to rebuild it. There are many companies which offer engines from wreckers, or direct parted out from Japan, but quality is always a question over here.

A good friend of mine bought a "contract" engine (as they are called here) and while it checked out ok on the stand, he still had a boatload of problems with it.

The guy who offered me his 4.2 is an acquaintance and he runs in the Patrol Club over here. He has offered the complete drivetrain to swap into mine - engine, gearbox, front and rear diffs. For that reason I am willing to negotiate with him so that I don't have to hunt down diffs to match the TD gearbox. Still in talks with him about it, so we'll see what happens.

Good luck with it he sounds like a fair bloke.
No thoughts of slotting in a BMW motor or
just way too expensive,,,,,,,,,,,,,lol

Yup. I need the ultimate in dependability up where I am, not crazy HP and torque. Our vehicle taxes over here are based on engine HP, anything over 250hp is ridiculously expensive. Hence the attraction to powerful diesels - great power but lower HP numbers.


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Thought about a Toyota 4.2. I think it's the 1Hz motor? I know they are extremely reliable as well. Not sure which one would be the most reliable - Nissan TD42 or Toyota 4.2?


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Well looks like I'm going to pass on this one for the time being. The guy was willing to negotiate the price of an overhaul, but the main issue is time right now. I haven't been able to get my Patrol down to the city yet (via ice road), so there wouldn't be enough time to overhaul the engine and get everything swapped over before the ice road melts and cuts off access. It may be an option next winter if I get it down in the beginning of the season, then there will be plenty of time to do the swap.

For now, I'm just going to stick with getting the valves done and head gasket replaced on my RD. Couple of day job at most and then I should be back up before the ice road closes. One of the downsides of living in way out in the bush in Siberia ;)