How To Replace Turbocharger Allis 190XT

Removing Turbo

Remove the cowl in front of the steering wheel, and disconnect all wires from the regulator.Make a note of the wires coming into the regulator before removing  them.  A digital pic is handy.Remove the exhaust stack, and radiator cap.The hood will have to be tilted to the left side of the tractor (looking from the drivers seat) to clear some hard lines.  Then it must be lifted straight up to clear a bulkhead.Once the hood is removed, the main intake/output ducts are visible.Manifold is the compressed air going from turbo to engine intake manifold.  Fresh air duct brings air from the air filter ahead of the radiator.

The next step is to remove the hoses connecting the manifold/fresh air duct to the turbo.Remove the clamps, and use a large pair of slip joint pliers to gently twist the hose to break it free.  Be careful not to damage the hose.  They’re expensive.

The intake hose is separated by loosening it, twisting it to break it free, then tapping the steel ductwork rearward to dislodge it from the turbo.  Use a rubber mallet while applying rearward pressure to the duct.   All duct supports must be loosened to allow the duct to move.It helps to reinstall the rearward hose clamp to provide traction for the hose, so that it will actually pull off the turbo without coming off the duct. 

Next is the manifold duct.  It’s removed in the same way.  NOTE THAT THE STEEL DUCT IS GENERALLY REMOVED ALONG WITH THE HOSE.Slide the hose off on the intake duct, then remove the duct from the manifold.  A new gasket may be required, but sometimes it’s not necessary.  In this case, I was able to save the gasket, but there was minor damage to it.Some of the gasket material may stick to the duct flange.  If it’s not severe, the gasket is salvageable when reinstalling the duct.  IF PART OF THE GASKET STICKS TO EITHER THE MANIFOLD, OR MANIFOLD DUCT, DON’T SCRAPE IT OFF……LEAVE IT ON THERE IF YOU CHOOSE TO REUSE IT.

High pressure supply line, and oil return line, are removed next.  This line has been leaking since I’ve owned the tractor….spraying oil all over the right side of the engine.  Turns out that the previous owner had used silicone to originally seal the gasket.  Geez!!!!NEVER USE SILICONE FOR THIS TYPE OF APPLICATION.

Next, the turbo itself is removed.  Be ready to do some damage to the mounting studs.  Exhaust studs are notorious for seizing, and breaking.

In this case, I’m using a box end wrench due to clearance issues.Naturally, it won’t budge…….so add a cheater.DON’T LEAN ON THE CHEATER……GO GENTLE.

I like to use penetrating oil prior to attempting to remove exhaust studs.  Sometimes it helps, sometimes it doesn’t.  This time it did (happy dance!!!!)I try to spray repeatedly, and let it set over night if possible.  It’s a gamble either way.

Repairing Damaged Studs

In this case, 3 of the studs came loose with no problem.  The 4th stud couldn’t be broken loose because the turbo housing prevented me from using the box end of the wrench.  I could only gain access with the open end.  The open end of a wrench is too flexible to apply any meaningful torque, so the nut had to be cut off, and the stud cut out of the flange.  I highly recommend using a plasma cutter when working with studs.  They’re instant cutting, and fast.  This helps to prevent igniting the grease on the engine.  An Oxy Acetylene torch requires a long preheat, which can lead to fires.

Normally, the plasma makes a very clean cut.  But in this case I was standing on the ground, reaching over the top of the engine to make the cut.  Couldn’t get a good view of the hole I was cutting.I can’t really complain though.  It’s a relatively clean cut, with no appreciable material loss from the flange.  This would be hard to do with a regular O/A torch.  And there’s no excessive heat input to the flange…..possibly causing brittle issues.

The hole is cleaned up with a die grinder with a 1/4″ straight double cut point.  Always use double cut points.  They remove material faster.  If you have access to an electric die grinder, so much the better.  Air powered die grinders lack the power to remove material fast, and clean.Using a spare bolt of the same size, resize your hole to fit.The old turbo gasket will be helpful as a template to accurately locate/size the hole.

Once the hole is sized, it’s time to make sure the flange is clean and flat.  I like to use a machinists square to verify the flange surface.  Any straight edge will do though.You might notice that the remaining studs have some thread damage near the upper end.  This is simple corrosion, and that portion of the thread is no longer suitable for use……BUT…..the remaining undamaged thread is where the nuts were when the turbo was still bolted to the flange.  THIS SECTION OF THE THREAD IS USEABLE, AND THE STUD CAN STILL BE USED.

Now, we’re ready to install the new turbo with 3 studs, and a bolt substituting for the damaged stud/hole.

Clocking The Turbo

Virtually any turbo you buy, will be assembled with all of the fittings in the wrong orientation.  You have to clock it to bring the fittings in line with hoses, and lines on the engine.

This is the new turbo out of the box, and how the fittings are way out of alignment.The turbo housing is a three piece affair.  All of these pieces can be rotated to fit your engine.

Clamp bolts are on the impeller housing, and compressor housing.

Impeller Housing

These bolts are all around the circumference of the housing, and need to be slightly loosened to allow the center bearing housing to rotate.  JUST LOOSE ENOUGH TO ALLOW MOVEMENT.

Compressor Housing


You may have to partially rotate the turbo off the engine before temporarily attaching it to the engine.  Temporary attachment, with flange bolts finger tight, will allow you to fine tune the housing orientation to fit your on-engine fittings.Then you rotate the bearing housing, and compressor housing, to align with your engine components.  DON’T EXPECT A PERFECT FIT.  The reason the components are attached to the turbo with rubber hose, is to allow for slight alignment differences.Note that the manifold duct has been temporarily installed for the fitup.  Don’t permanently install it at this time.

The oil return line is aligned in the same manner.Now lightly tighten the bolts on the compressor housing, and impeller housing.  Just enough to allow you to remove the turbo in order to fully tighten the bolts on the bench.

Remove the turbo, and final tighten the bolts.Use a standard box end wrench to tighten the bolts. DON’T USE A HONKIN’ BREAKER BAR.  You simply need to tighten them firmly with a standard wrench.  Over tighten, and you can possibly distort the housings, or strip the thread.

Mounting It On The Engine

Because I had to cut a stud out of the flange, it’s now necessary to substitute a standard bolt in that hole.

To clear the exhaust manifold, the bolt head has to be trimmed.Trim the head so that you leave yourself flats to accept a wrench when tightening.  Trimming in this manner, although weakening the head somewhat, is the only viable alternative.  Sometimes you gotta do what you gotta do.As you can see, it’s the only way the bolt can be inserted without interference.

Final tightening is the same as you did with the housing bolts when clocking the turbo.  DON’T GET CARRIED AWAY.  GOOD AND TIGHT, BUT DON’T BREAK THE STUDS/BOLTS.Remember to install the metal gasket with the ridged side facing up, and you’re good to go for the next step.

Reinstall the manifold duct at this time.

Because I chose to keep the old gasket, it will need a sealant (a new gasket would be installed without sealant).I like this stuff  It’s worked out for me real well over the years.  I prefer it to anything Permatex makes.

Coat all surfaces with a generous amount of the sealer, and bolt it back on the engine.You need a generous amount because the damaged part of the gasket is now porous.  Done properly,, you’re good to go, and won’t have sealing problems.  DON’T OVER TIGHTEN.

Reinstall all the ductwork in the reverse order of taking it off, using the same techniques.

The oil hard lines have to be done carefully, or they won’t seal.

Clean the return line gasket flange after removing the line entirely from the engine.

Install a new lower rubber hose on the return line at this time.  Don’t try to reuse the old hose, it’s likely swollen from oil, and won’t seal properly.  Heater hose works well in this application.

Slip the return line into the lower rubber hose next to the block.Only tighten the hose where it goes to the block, leave the other end with the metal tube loose… has to move in order to install the hard flange at the turbo.

Using the same sealant, coat all surfaces of gasket, tube flange, and turbo inlet flange.  Assemble and tighten (don’t over tighten).The reason you left the lower hose loose was to allow movement to align and tighten the hard flange.  IT HAS TO MOVE.  After tightening the hard flange, you can then tighten the lower hose.

Next is the high pressure inlet line.  Use Teflon tape to seal your inlet fitting.  It’s good because it forms a tight seal, and can be removed easily sometime in the future if need be.  DON’T USE PIPE DOPE, IT FORMS A HARDENED MESS THAT’S HARD TO REMOVE IN THE FUTURE.Make sure to wrap the tape so it won’t bunch up when the fitting is installed.  Wrap it in the opposite direction of when the fitting is tightened.  4-5 wraps is generally good.  Again…..don’t overtighten…it doesn’t help it to seal, it just makes things more difficult to tighten to final position.




I chose to reuse the old ferrules, but it’s a good idea to get new ones if possible.  Use the plastic ferrules, they won’t crimp the tubing, and allow for a greater angle at fitup.  Do the hardest fitup first….in this case, the top fitting required the most finagling to get it to line up, so I did it first.  The second bottom fitting was then wrangled into line.NOTE THAT SOME OF THESE LINE FITTINGS MIGHT HAVE TO BE PARTIALLY INSTALLED AT AN EARLIER POINT IF YOU SEE THAT ANYTHING WILL INTERFERE WITH THEIR MOVEMENT ONCE THE TURBO HAS BEEN CLOCKED.  JUST A HEADS UP.

The Exhaust Flange

Remove the old turbo with the exhaust flange attached, do NOT try to remove it when on the engine.  It just ain’t gonna happen.

I don’t care to fight with decades old rusted bolts, so I cut these off with a torch.  BE SURE TO DO YOUR CUTTING ON THE OLD TURBO SIDE OF THE FLANGE, NOT ON THE FLANGE SIDE.  You don’t want to damage the exhaust flange, they’re pricey.If you look carefully, you can see the reason the turbo needed replacement.  Note the marks on the housing where the blades have been touching it.It’s not the worst, but it’s on its way to getting bad.  The turbo whined when running, and clattered when the engine was shut off, and it wound down in the housing.

The seal had also started to go bad, and was allowing oil into the compressor housing.

The exhaust flange can now be installed while the new turbo is on the engine.Again, don’t go crazy when you tighten.

Also note:  There is no gasket here.  The flange seals when the carbon buildup fills any gaps on the machined surface inside the lip of the flange.  It’s the way they’re designed.

A Note On Chemicals

All threads on the turbo flange are coated with anti seize before assembly.  I like the high temp copper stuff.The squirt can is used to fill the upper high pressure inlet prior to assembly.

Final Check

Any day above ground is a good day

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