edwinsmith

I have the 1989 D350 dually. Does anyone know how to tell what turbo housing I have? I'd like to swap it out for the 16 cm housing which seems to be reccommended by everyone to get more low end power.

Is an EGT more critical to have with this setup? I plan to haul a 32' 5th wheel trailer.

Thanks

Edwin

wannadiesel

Unless somebody's been in there and swapped it already, you have an 18.5 cm housing. You can verify this by reading the number cast into the firewall side of the housing. This requires a flashlight and a mirror unless you're very flexible.

The 16 cm housing is good for two reasons. First, it will provide boost more quickly during acceleration, which makes the truck more fun to drive. Second, it increases the boost pressure at full power, which helps keep the EGT under control when pulling a heavy trailer up a steep hill.

EGT is critical on any truck that is working for a living or has been modified. For what you're doing, I'd say a pyrometer and a trans temp gauge (if the truck is an automatic) are very important. You will probably have more power available than you can safely use all the way up a long hill, and these two gauges will help you keep from hurting the truck.

edwinsmith

Thanks.

What is the number on the 18.5 cm housing?

I have I believe the Getrag 360 5 speed tranny which I figured I would use until it breaks then swap it out for something beefier. It shifts great but then I haven't pulled much with it yet.

Any recomendations on a Boost/EGT guage combo?

Edwin

wannadiesel

Believe it or not, the size is cast into the back of the housings. Why did they make it so simple?

The Getrag seems to be pretty tough provided you overfill it by one quart and use synthetic oil. 5W-30 or Redline MTL work well. The bearings are actually set up with preload so it does not tolerate heavy gear lubes.

The AutoMeter Z-series gauges match the factory gauges well. If you want a pyro/boost combo in one gauge, Westach is the only game in town I think.

mhuppertz

If your Getrag does blow, say pulling a fullsize van on a tow dolley up the caprock to Amarillo, you can now replace it with an NV4500 or even better an NV 5600 6 speed for just a little more than getting the grenaded Getrag fixed or replaced. The Getrag has a ratio spacing problem between, uh second and third if I remember correctly that the NV4500 does not have.

jleonard

The Getrags seem to last longer in the 2wd version. Downshifting to 4th with a load on rather than lugging in 5th will help it's longevity.
And overfilling as stated above.
Have fun.
Jay

edwinsmith

I looked at my turbo housing today and it appears to be the stock 18 cm. I saw an 18 all by itself and a bunch of other numbers which I didn't record. (cold north wind blowing up my dress.)

What is involved in replacing the housing with a 16 cm other than disassembly and re-assembly? Bear in mind that it's 15 years old and bolts are rusted etc... So other than spraying it liberally with wd-40 a day before how hard is the thing to get off?

Edwin

wannadiesel

TST's install instructions are pretty good. The only thing I'd add is to not bother with trying to do it with the turbo on the truck. Pull the turbo, it's easier on a workbench. 4 nuts, 2 bolts, and 3 clamps and the turbo is in your hands. The worst thing about the job is getting the rock-hard remains of the drainback tube gasket off turbo and drain tube. Don't be surprised if you have to wail on the housing with a big hammer for a while to make it move, I banged on mine for 20 minutes before it moved. Once it moves, switch to a smaller hammer and be start being careful.

Bushy

The bolts that hold the turbo and it's hot end housing together are stainless. You'll have no problem there.
The bolts that hold the turbo to the exhaust manifold are gonna be tough. Just start a week early and blast em with PB Blaster or other good liquid wrench stuff.... soak em good, in fact the more often you do it the better it'll be.
Your biggest headache will be seperating the old housing from the turbo.
I did one today as a matter of fact.
I had to use a mechanic to hold the turbo while I wacked the exhaust housing with a 3 lb sledge.
You need to use care here.... as you wack the housing to get it off keep using your fingers to twirl the compressor blade on the front end of the turbo. When you fill it start to scuff, you need to rotate the turbo and wack the opposite side. Keep checking real often so you don't bind up the impellor blade inside the exhaust housing.
It will come off, but it is a DEFINITE booger to do after all this time..

bob....

dzpoorjr

I found a HOLSET HEX55IV in 16cm2-will the inards from my stock 18cm2 go into this housing. Thanks ahead as usual!