Need opinion on transmission

[RSchwarzli]

Need opinion on transmission - Getrag Swap or Gear Vendors?

Well, goes like this. I am tired of high rpms on long highway drives in the 1990 Auto. I happen to have two options and I need some advice on what to do!:{



Getrag - I have a fully rebuilt and beefed getrag sitting in the garage complete with petals. All I would need is hydraulic lines with cylinders (master and slave) and a clutch/flywheel assy. I would also need to modify the NP205 to work with a stick trans.



727 - On the other hand, I have a good condition 727 in the truck and I just inherited a Gear Vendors unit. I can change the torque converter ($750 for a DTT unit) to be able to handle the overdrive with trailer towing and while I am at it do a valve body upgrade for another $200 or so. I will also need the GV adapter ($500) so that the overdrive will mate to the NP205.



So thoughts? Opinions? What should I do? Part if the issue is I have a bad problem with seeing what can be done as I have so much of both available yet I do need to collect me pieces eityher way. Cost I am guessing is about the same.



Need some advice. Badly!:-laf



Robert

 

[MMeier]

If you really know what you have in that getrag, use that. Otherwise swap in a 4500. Best thing I've ever done to a 1st gen truck !!

 

[Bob Beauchaine]

I would also go with an NV4500D. It was the best swap I've ever done on my '93. With 354s in the rear diff. I see 1850 rpms at 70 mph. The NV is also much quieter than the Getrag plus tighter shifts.



Bob

 

[Tippin Spotted Cow]

Modifying the NP205 is not as easy as it sounds. You have to tear the thing apart down to an empty case. Machine the front of the case and the bearing retainer to accept the larger shaft and bearing. Buy a 29 spline shaft, which when all is said and done, between the gaskets, beaing, shaft, and 29 spline coupler, this will run you right around $500. Then you need the adapter, or "transfer case bellhousing" as some call it. It is similar to the auto version, but larger, once again to fit over the bearing. You can machine out the auto version, but it doesn't leave much meat, so you have to be very careful. I've even heard of some people using a filler material in the thin spots before machining just to stay on the safe side. You might be better served just buying an NP205 out of a junkyard somewhere or from craigslist. The 29 splines are very rare though. Expect to pay $400-600 plus shipping for one. The ONLY place the right drop, 29 spline, NP205 was EVER used was in the 89-90 Cummins Rams with a Getrag, and these don't often get scrapped.



On the diesels, you don't have a master cylinder/lines/slave cylinder. You buy it as all one assembly, roughly $300.



A decent clutch will run you between $500 and $1000 (usually including a flywheel) depending on your application.



I've been working on the same project, gathering parts for a while now. I had more than a few monitary setbacks, causing this project to STILL be looming over my head right now, but in the mean time I've gathered a lot of information, so if you decide to go this route, I'd be more than willing to help.

 

[RSchwarzli]

I agree with the 4500, I have two thoughts on that though.



1. I would then need to get another transmission when I already have two



2. I started to go that way with the crew cab, then I got out of contol and ended up with a 4 year restoration and a NV5600!



As much as I agree that would be the way to go, I am going to TRY HARD to stay with one of the two (Getrag or 727) that I currently have.



Got me thinking though Bob with your post. Maybe though I should also be mentioning that the truck has a 3. 07 rear...

 

[RSchwarzli]

Mr Cow Sir,



Thanks for the info as well! That makes it pretty black and white! So I guess a t case would be needed then for the stick swap. Added to the list now...



The Overdrive is starting to look easier but less fun!

 

[Dieselman359]

Try the cheaper option first

Bob, as you and I both know, when you start pouring $$$ into these 16+ year-old trucks, it can get out of hand real quick! My vote is to install the GV, and see how it works with what ya got. I don't know what your GV came off of, but mine was originally a remote mount (installs where your carrier bearing was in a two-piece driveshaft) when the truck was a 2X4, but instead of mounting it to the 205, I left it where it was and shortened the driveshaft b/w the GV and 205. Hopefully yours is set up that way, but I'm sure if it was you would of already installed it and not be asking for opinions. :-laf



Otherwise, weigh your options, as for me, I'm done pouring $$$ into these trucks. No more 4X4 conversions for me!

 

[RSchwarzli]

Yup. We both have problems when it comes to these trucks!



As for the GV, you are correct. That is why the adapter is needed. Was off a 1973 727 340 Duster. So I will need to mate it to the T case. If it was a remote... well that would be really easy! Oo.



Ok. So 1 vote for the GV.



Anyone else?

 

[Dieselman359]

Damn

Well that sucks. I was hoping that we could make this easy for ya. I recently found out that GV parts are not cheap. Tough call, let us know what route you take. I still think that the GV would be the most 'cost effective' move. Notice that I didn't say cheap.

 

[RSchwarzli]

Yes, I did notice your choice of wording.



If anyone has any thoughts or ideas, just say so. I am always open to them.



I really did not think this was going to be such a tough choice but the more I think.....

 

[Tippin Spotted Cow]

Personally, I have not had much luck with autos, and I think they're garbage. I'd much prefer a stick, which is why I'm planning the swap on mine. If you have the time, money, and ambition, I'd put a vote in for the Getrag.

 

[RSchwarzli]

So, 1 for 1... .

 

[braml]

i have a rebuilt auto in a 1995 3500 all stock with a shift kit and transfercase with about 4000 miles on it for sale call me 605 359 2043

 

[RSchwarzli]

Am I correct on believing that this will not fit into an 89 without some computers and a different front axle (drivers vs passenger side axle drive)?



I do appreciate the offer but I have too many tranies already! That is where this all started! Way too many options... .



Welcome the the forums by the way!

 

[cerberusiam]

Am I correct on believing that this will not fit into an 89 without some computers and a different front axle (drivers vs passenger side axle drive)?

Physically, the 47RH is a direct bolt in with the correct engine adapter. It will bolt to the 205. Other things needs some modifications like t-case mounts, starter, etc, but those are relatively easy.



If you are not picky about it, OD can be controlled with a simple switch, a Hobbs switch, or just an electronic speed monitor. Lockup the same way with different parameters. Depends on how much you want to tinker and how much you want to spend.



Unless you have a parts truck for the manual conversion its a toss up as to which one is a "better" choice. You will have to tinker with either of the installs. With the manual its modifying the t-case, with the auto is modifying mounts and engineering some electrical controls.

 

[RSchwarzli]

I think I have made up my mind. I think I will go with the Gutbag as it is freshly built with HD internats and I really want an E brake! Also I like shifting so... .



Anyone know of a clean, unabused T case and hydraulics?

 

[Tippin Spotted Cow]

There's a junkyard in... Alabama... . or one of them southern states... that specializes in diesels. Last time I called there they seemed pretty sure they had a few 29 spline 205s. $500 plus another $100 for a core charge. They'll accept your 23 spline as a core, but you'll pay more in shipping than its worth. It's some goofy name of the place... I'll check all my records and get back to you. ("Records" is used loosely... very loosely, here)

 

[RSchwarzli]

Maybe you should check your CD's.



Might have better luck.

 

[Mel Fuelling]

When I put a Southbend Clutch with the larger T/O bearing in a new flywheel in my 93 work truck, my Getrag suddenly became quiet.

 

["Mad Max"]

Rob,



I recently picked up an '89 RC (IDually's old truck) with '91 CTD/727 guts, and the 3. 07 D61/71 axles. I'm running the 31" standard tires and I will say this - I love the truck! It drives fantastic around town and the low gears are perfect for a daily-driver, especially behind an engine that loves low rpm cruising. It get's 20 mpg all day long. Granted it too spins a few hundred more rpm than I'd like, and I too will be swapping an overdrive transmission, but there is no way I will put in anything other than a 518. The 518 is a great transmission, and when properly equipped (good TC) it'll be absolutely perfect, at least for me. There is NO WAY I want to jack around with clutch linkage, bellhousings, adapters and all that crap. Granted I don't have a computer, so I'll use a simple Hobbs switch to activate/deactivate the overdrive. The only 'mods' will be to move the transmission crossmember back a bit and do some driveshaft adjustments.



Brother, seriously, keep yer life simple. I say 518 all the way.



- Sam