90 dodge cummins

;D hello everyone <br><br>first off some background<br>i am learning to be a mechanic and dont know too much about diesels yet sooooooooo.....<br>recently my brother became the owner of a pristine 1990 4x4 dodge d 250 with the cummins diesel backed by the a-727 three speed automatic, well what our problem is that the truck will only go 70 mph! so guess who my brother came too to fix the problem?<br><br>what i am trying to figure out is how hard it would be increase the top end speed without sacrificing torque<br>has anybody had this problem? if so i would appreciate your insights on how to fix this trouble<br><br>some thoughts i have had are below<br>install a A-518 4spd auto and if so what sort of modifications would be required<br><br> trying to increase top rpm limit to get speed that way or<br>looking into getting a gear vendor under/over drive or something<br><br>thanks for anyones help

Bushy

&quot;....1990 4x4 dodge d 250 ....&quot;

The two wheel drive series is usually labelled D250 and the 4X4's are labelled W250.

The 727 is a good tranny. It, like all needs regular servicing to hang onto the low end grunt that the diesel puts to it, but still a reliable transmission.
Since the tranny is only a 3 speed you need to adjust your &quot;high idle&quot; or governor screw. You will also need to make sure that, after doing so, the throttle peddle will pull the throttle arm all the way and make contact between the high idle screw and throttle stop.
Here is a link to pics I have of the various screws etc...
http://www.turbodieselregister.com/u...mp;albumid=453

You will need to remove the tamper cover from the high idle screw, then loosen the 2-10mm locknuts. MARK YOUR ORIGINAL POSITION !!!!!
Once the lock nuts are loose, back the screw out (counter clockwise when viewed from the rear/firewall end) about 3 turns. Tighten locknuts and test drive.
You really need a tach that is working properly, and aim for a max RPM of about 2900 ~ 3000 RPM in 3rd (which is 1:1)
You may need to repeat this depending on your current max RPM.

Again, make sure that the high idle stop plate, contacts the end of the high idle screw you backed out. Just look closely at the operation of the throttle from normal idle thru to WOT and you'll see the plate contact it as it is now..
That should get your started.
bob.

Caincando1

Are you running out of pedal or just speed? My 90 W250 was the same way when I bought it. 65 maybe 70 with the pedal mashed into the carpet. I took it to the local injector shop. They set the overhead vlaves, rebuilt the pump, and turned it up 10%(not sure what the means). Now I have no problem running 75-80. I've never ran any faster but it sure feels like there is plenty more.<br><br>Brian

90 dodge cummins

thanks for replying everyone<br><br>ok heres some more info on my problem<br>in answer to bushy's post thanks for the information.<br>i tried to see what sort of rpm i was turning, pedal to the metal. i was running about 2700 - 2800 rpm to the wall running about 73-75mph<br>so im not sure i have too much room to adjust while still staying whithin the limit of 2950 maximum rpms<br>as i said before i'm new to this diesel stuff so i don't<br>whats ok and what isnt as far as adjustments go.<br><br><br>also as far as getting the pump turned up 10% or so <br>do you remember what the cost was to have this service the performed? <br><br> Thanks all<br> Andrew<br><br> :

Bushy

You can set your WOT to 3000 RPM. You can also &quot;turn your pump up&quot; for 0 $$.<br><br>You can gain a fair bit with a few simple tools and some time... for the 1st timer who's never 'taken a chance' you would take about 1 hour for all of it, including the pump tweaking.<br>Don't pay for something like that unless you absolutely certain you don't wanna try it yourself.<br><br>Bob.

Caincando1

I took my truck to a reputable injection shop here in town. The bill was $800...Ouch!!! But I've been told this is about average. As for turning it up 10%, they to that to every 1st gen. that comes throught the door. <br><br>Brian<br><br>

furious70

if he's already pushing 2800rpms turning the pump up is not gonna help him much guys! IMO if you want to improve mpg and be able to move faster you need to get an OD in there. Hard to say which is easier/cheaper, none will be cheap with the 4wd in the way.

Bushy

The A-518 is a 727 with an OD added. You can change out the basic 3spd 727 pretty easily. The probems are minor and include adding the OD button on the dash, and some basic wiring, tranny mount, possible driveshaft mods.
The real issue is the cost of getting a good A518 to put in. You will likely find that a &quot;new&quot; tranny is in fact a rebuilt one.
They've been around long enough now that DC is no longer making &quot;brand new&quot; ones, but re&amp;re'ing them.
If you have the budget, then get DTT to build you one with the full meal deal. You can choose between various effficiency TC's, VB's, and tranny setups. You won't believe the difference. My tranny setup in your truck will carry you well over 100 MPH easily, it does in mine...
The cost?? Not all that far off a &quot;new&quot; A518, which is WITHOUT TC, VB. !!
If the budget won't support that, then look at picking up an OD unit from a wreck, or the entire unit (less transfer case). You can have the seals updated and the VB tuned a bit, a good pressure testing session will help.
BTW, the NP205 is a good transfer case, it's all gear driven, no chains or belts etc. Do not part with that.
Last choice would be a diff change, to lower ratio's. That is pretty pricey too.

I don't know if that helps, or hurts....

bob.

furious70

is the output shaft of the 518 the same as the 727? i.e. will his Tcase bolt up to a 518 with no changes?

Bushy

You know, I honestly don't know 100% on that one......<br>I have been told that all DC did was mate up an OD unit to the already decent 727. Now, I've always assumed they were totally compatible, but then assumptions are not good things to bet on...<br>A quick phone call to a tranny man will turn that one up though...<br><br>bob.

90 dodge cummins

hello again everyone!

thanks for all the posts so far

i just checked the no load max rpm whith a digital photo tachometer acurate +/- .5 percent and it said i was running at 2860 rpm no load, according to this i dont have much room for adjustments to my rpm range, seeing as max recomended rpm is 2950. so the easy fix route is out!
:'(
and since the diff ratio is already at 3.07 its hard to get speed through changing the front and rear diff gears. leaving me with the 727/518 swap as my most logical option. how ever this is where i run into problems.......
im looking for a relativly inexspensive fix to the problem so i would probably do the tranny myself.
there enlies the trouble

no salvage yard i have called yet even has a dodge diesel truck in their yard!!!! it seems no one in my area wrecks these trucks! &gt;
anyone know of some place where i could obtain the nessesary components? i.e. tranny case, rebuild kit (hard parts, soft parts) etc..

you guys help is appreciated!
any suggestions are appreciated as well

Caincando1

Now I'm curious as to what gears I have in my truck. I stood on it the other day and shut it down when I approached 85mph. And thats with a 90 w-250. How do I tell that gears I have?<br><br>Brian

Bushy

How about this as a possible option...<br><br>You should contact Bill Kondolay. He has some extremely effective high efficiency convertors for us.<br>Since your truck, like all 1st Gens, does not use a lockup convertor your costs are less than the newer trucks and there is no arguing over tranny companies.<br>Talk to Bill about your situation, explain your needs re: higher top end. (BTW readjust your gov. to take you to a full 3000 RPM)<br>You may be able to add an 89% or even 91% TC, a tuned valve body, and a seal and clutch update kit for a reasonable price. The difference in top end using his system is really something. You will definitely gain top end, really see acceleration differences and likely need new tires more often.<br>Just a thought, and the phone call is cheap since it's toll free.<br><br>Heck, tell them I advised you to call. BTW I get nothing for helping you make contact with them accept the satisfaction when your problem(s) get fixed.<br><br>bob.

90 dodge cummins

ok thanks bob for the info on bill kondolay<br>but one problem<br><br><br>what is his number?<br><br>hopefully he'll be able to help me<br><br><br>also back to my problem <br>ok i checked my high rpm no load and it was 2860 rpm<br>should i try adjusting it so i have a total of 3000 rpm under load? i talked to a diesel instructor at my school and he said it would be possible to go into valve float if adjusted too high.<br> by setting rpm under load wouldn't it cause no load rpm to sky rocket?<br>just a thought. <br><br>you guys are great! <br> <br>

Monty

You can find Bill at http://www.dieseltrans.com